JPS6242518B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic musical instrument in which keys pressed on a keyboard are classified into one of a plurality of groups, and musical tones can be formed in a different manner for each group.

Generally, a keyboard with multiple keyboards (for example, an upper keyboard, a lower keyboard,
In electronic musical instruments equipped with pedal keyboards, etc., the melody and accompaniment are played on different keys, and the melody and accompaniment sounds are played in different modes (typically, tone) that are selected and set for each keyboard. The musical tones are formed respectively. On the other hand, single-keyboard electronic musical instruments are often useful due to cost and transportability when used for stage performance, and it is possible to play the melody and accompaniment separately in such single-keyboard electronic musical instruments. In order to obtain this, a technique called "key range splitting" is adopted.
Conventional "key range division" technology uses a predetermined specific key as the boundary, and uses the treble range of that key as the melody key range, and the other (lower range) keys for accompaniment. The musical tones corresponding to the pressed keys in each key area are formed as melody tones or accompaniment tones. That is, the melody key range and the accompaniment key range were fixed in advance and remained unchanged. As a result, the keyboard range that can be used for melody or accompaniment is limited to a narrow range. Particularly in single-keyboard electronic musical instruments, the total number of keys on the keyboard tends to be small due to cost or transportability considerations, which further limits the range of each key range when dividing the key range. This may hinder the freedom of performance.

This invention was made in view of the above points,
When the keyboard is divided into a plurality of groups corresponding to different musical tone formation modes, the key range corresponding to each group is not fixed and can be automatically set according to the key depression state. The purpose is to avoid being limited by the range of keys used in actual performance. In order to achieve this object, an electronic musical instrument according to the present invention includes a keyboard, a key press information generating means for generating key press information corresponding to a pressed key on the keyboard, and a chord selected from among the pressed keys on the keyboard. chord detecting means for detecting a plurality of pressed keys forming a chord, and a pressed key forming a chord among the pressed key information generated from the pressed key information generating means based on the detection by the chord detecting means. a discriminating means for discriminating key press information corresponding to the pressed key information and key press information corresponding to other pressed keys into separate groups, and a musical tone signal corresponding to the key press information discriminated into each group by the discriminating means. The present invention is characterized by comprising musical tone forming means for forming musical tones in different manners for each group. In groups in which pressed keys constituting a chord have been discriminated, musical tones are formed in an accompaniment manner, and in groups in which other pressed keys have been discriminated, musical tones are formed in a melody manner. Usually, accompaniment performance is performed by pressing multiple keys that make up a chord. Therefore, by distinguishing between pressed keys constituting a chord and other pressed keys, it is possible to distinguish between keys pressed for accompaniment performance and keys pressed for melody performance. . Note that the tone formation mode refers to the mode of factors for forming a musical tone, such as timbre, volume, envelope shape, pitch, etc., and a different tone formation mode refers to a difference in one or more of these factors.

Depending on the piece of music to be played, the pitch of the melody notes may approach the range of the accompaniment chords. In such a case, it is advantageous to classify only the pressed keys forming the chord into the accompaniment group, and to classify the other pressed keys into the melody group. In this way, even if a melody note is pressed in the vicinity of an accompaniment chord, the pressed keys for melody performance and the pressed keys (chord constituent keys) for accompaniment performance can be reliably distinguished. The embodiment shown in the drawings shows such an example. However, in addition to the pressed keys (chord-constituting keys) constituting the consonant chord, an extra key may be mistakenly pressed in the vicinity thereof. In such a case, it is preferable that the extra key be sounded as an accompaniment sound rather than as a melody sound. Additionally, chord detection circuits for electronic musical instruments generally use major, minor,
In many cases, we use chords that can only detect typical chord types, such as sevenths, and in such cases,
If a chord that cannot be detected by the chord detection circuit (for example, Sixthus) is pressed with four or more keys, a chord that can be detected by three of those keys (for example, Major) will be mistakenly detected, and the remaining keys, which are originally chord constituent keys, will be pressed. There is also the possibility that the key may be mistakenly identified as a key for a melody group. In order to eliminate such inconveniences, the pressed keys that make up the chord and the pressed keys in the vicinity (for example, all keys within a certain pitch range including the keys that make up the chord) are separated into accompaniment groups, and other It is preferable to distinguish the pressed keys into melody groups. Therefore, in the second invention, based on the detection by the chord detecting means, the key range indicating means indicates the key range over a certain pitch range to which the pressed keys constituting the chord belong; The present invention is characterized by comprising a discrimination means for distinguishing pressed key information corresponding to pressed keys belonging to a key range and pressed key information corresponding to other pressed keys into separate groups.

Another object of the present invention is to make it possible to distinguish the pressed keys into accompaniment groups even when one or more keys that do not constitute a chord are pressed for accompaniment performance. For example, when playing automatic bass chords in single-finger mode, press one key on the keyboard that corresponds to the root note of the chord,
The chord type is specified using a separate appropriate means (a dedicated switch or the white and black keys of the keyboard), so even if you specify an accompaniment chord to be pressed, the pressed keys on the keyboard will not constitute a chord. I haven't. Furthermore, even if the user intends to press the keys so as to form a chord, due to an error in key operation, the keys actually pressed may not form a chord. As described above, it is possible that one or more keys pressed for accompaniment performance do not constitute a chord (consonance), so it is necessary to be able to deal with such cases. Therefore, the electronic musical instrument according to the third invention includes a keyboard consisting of a first keyboard area, a second keyboard area adjacent thereto, and a remaining keyboard area, and key press information corresponding to pressed keys on the keyboard. A means for generating key press information to be generated;
Based on the key press information generated from the key press information generating means, it is determined whether a chord is formed by a plurality of pressed keys belonging to at least one of the first key range and the second key range. The chord detecting means to be detected and the key press information of the pressed keys belonging to the first key range are always distinguished into the first group, and the second a discrimination means for discriminating key press information of pressed keys in a key range into a first group and discriminating key press information of other pressed keys into a second group; The present invention is characterized by comprising a musical tone forming means for forming musical tone signals corresponding to key press information in different manners for each group.

If the first group is an accompaniment group and the second group is a melody group, the first key range corresponds to the accompaniment-only key range, and the second key range is the key range adjacent to the accompaniment-only key range. be. The remaining key ranges correspond to melody groups. The second key range is classified into either the first group or the second group depending on whether a chord is established or not,
It functions as a key range for accompaniment or melody, switching at any time. It is also possible to select the keys that make up a chord from among the pressed keys that do not belong to the accompaniment-only key area and classify them into the accompaniment group, but due to an error in key pressing, an extra key may be left in the vicinity of the chord-composing keys. It is also possible to press the In such a case, it is preferable to make the extra pressed keys sound as accompaniment sounds rather than distinguishing them into the melody group and emitting them as melody sounds, instead of distinguishing them into the accompaniment group. It is preferable that pressed keys are also classified into accompaniment groups.

The accompaniment-only key range is preferably set so as not to hinder the freedom of melody performance when the remaining key range is used for melody performance. To this end, it is preferable to use the lowest one-octave key range as an accompaniment-only key range.

In the embodiment, two modes are disclosed as modes for detecting whether or not a chord is formed by keys pressed near the accompaniment key area. One is a mode (hereinafter referred to as A mode) that requires that at least one of the pressed keys that is the target of chord detection belongs to the accompaniment-only keyboard area (hereinafter referred to as A mode); The key to be pressed must belong to either or both of the accompaniment-only keyboard area and a predetermined nearby keyboard area (for example, an octave area above the accompaniment-only area that consists of at least one octave area). This is a mode (hereinafter referred to as B mode) in which there is no longer a problem. In the embodiment, one of the modes (A or B) is selected by a chord detection mode selection switch.

In the embodiment, two modes are disclosed as modes for setting the range of the vicinity of chord constituent keys to be included in an accompaniment group. One of them is a mode in which the accompaniment group includes up to the highest pressed key (highest note) in the key range that is the target of chord detection (key range that combines the accompaniment dedicated key range and its neighboring predetermined key range). (hereinafter referred to as C mode), and the other is the accompaniment-only key range and a predetermined key range nearby (this may be set arbitrarily separately from the predetermined key range for chord detection). This is a mode (hereinafter referred to as D mode) in which all the songs are included in the accompaniment group. In the embodiment, the above mode (C or D) is selected by the key range movement selection switch.
one of them is selected.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block diagram schematically showing the overall structure of an electronic musical instrument in which the present invention is applied to an electronic musical instrument of a type in which pressed keys are detected by sequentially scanning each key on a keyboard. In this example, the keyboard 11 is assumed to have 49 keys from the lowest key C2 to the highest key C6. The multiplexer 12 as key press information generating means receives the system clock pulse φ.
Accordingly, each key on the keyboard 11 is sequentially scanned starting from the bass side, thereby assigning a time-sharing timing to each key, and generating pulses corresponding to the time-sharing timing of the pressed key. Pulses corresponding to the timing of pressed keys are multiplexed into one line and output as time division multiplexed key data KTDM. As a result of scanning by the multiplexer 12, a portion of the time division timing assigned to each key C2 to C6 is shown in the key scanning timing column of FIG. φ in FIG. 2 represents an example of the system clock pulse φ. One cycle of key scanning consists of 60 time slots. Forty-nine keys C2 to C6 are sequentially assigned from time slot 1 to time slot 49.

The time division multiplexed key data KTDM output from the multiplexer 12 is supplied to the chord detection means 13 and the discrimination means 14. The chord detection means 13 is
It is for detecting a chord from among the pressed keys on the keyboard 11, and includes a key range detection circuit 15 in which a predetermined number of pressed keys exist, a chord establishment detection circuit 16, and a chord constituent note extraction circuit 17. The predetermined number of pressed keys existence key area detection circuit 15 detects whether or not a predetermined number or more keys are being pressed in the vicinity of each other, and detects a predetermined number of keys that indicate a key area that includes the predetermined number or more keys that are being pressed in the vicinity of each other. Outputs several pressed key existence key area detection signal 3KD*.
The chord formation detection circuit 16 is for detecting whether or not a chord is formed by pressing keys within the key range indicated by the signal 3KD*. If it is detected that a chord is established, data indicating the type of the chord is provided to the chord constituent note extraction circuit 17. The chord constituent note extraction circuit 17 is a circuit for selecting a plurality of pressed keys corresponding to chord constituent notes from among the pressed keys within the key range indicated by the signal 3KD* according to the type of chord whose establishment is detected. , outputs a chord constituent note discrimination signal CHKD**.

The discrimination means 14 is for discriminating the key data KTDM into either a melody group (MKD) or an accompaniment group (AKD) based on the output (CHKD**) of the chord detection means 13. In this embodiment, the key data KTDM of pressed keys constituting a chord is distinguished as accompaniment key data AKD, and the key data of other pressed keys is discriminated as melody key data MKD.

A detailed example of the chord detecting means 13 and the discriminating means 14 is shown in FIG. In this example, two key scanning cycles are used for chord detection and discrimination. Generally, chord detection processing is performed in the first cycle (first cycle),
Discrimination processing is performed in the next cycle (second cycle). Timing signal generator 18 (Figure 1)
are the system clock pulse φ and the timing signals SY1, SY2, SY1*, SY1* for controlling various operations in the first cycle and the second cycle.
*, SY2**, HA*, HB** are generated. These timing signals SY1 to HB** are generated as shown in FIG.

The first cycle scan start timing signal SY1 is the first timing (time slot) of the first cycle.
60). Signal SY1* is signal SY1
It is delayed by 12 bits. Note that the time corresponding to one cycle of the system clock pulse φ, that is, the scanning timing for one key is referred to as one bit time. Signal SY1** is signal SY1 delayed by 24 bits. The second cycle scan start timing signal SY2 is generated at the first timing (time slot 60) of the second cycle. Signal SY2** is signal SY2 delayed by 24 bits. 1st cycle key scanning interval signal
HA* is a signal indicating the scanning timing from keys C2 to C6 (time slots 1 to 49) in the first cycle, delayed by 12 bits. Therefore, this signal HA* is "1" for 49 bit times from time slot 13 of the first cycle to time slot 1 of the second cycle. This signal HA* is synchronized with the timing at which data from keys C2 to C6 appear in key data KTDM* which is delayed by 12 bits of time from key data KTDM. 2nd cycle key scanning interval signal
HB** is a signal indicating the scanning timing from keys C2 to C6 (time slots 1 to 49) in the second cycle, delayed by 24 bits. Therefore, this signal HB** is 1'' for 49 bit times from time slot 25 of the second cycle to time slot 13 of the first cycle.
This signal HB** is synchronized with the timing at which data from keys C2 to C6 appear in key data KTDM** which is delayed by 24 bit times from key data KTDM.

Predetermined number of pressed keys existing key area detection circuit 1 shown in FIG.
5, a predetermined number (3
Key ranges in which the above keys are pressed nearby are extracted. The shift register 20 in the detection circuit 15 has 7 stages/1 bit, and the time division multiplexed key data KTDM output from the multiplexer 12 (Fig. 1) is applied to its shift control input, and the first cycle scan start timing is Signal SY1 and second cycle scan start timing signal
SY2 is applied via OR circuit 19 to its data set input. When "1" is applied from the OR circuit 19 to the data set input of the shift register 20, "1" is set to the first stage of the shift register 20, and the contents of the other stages are reset to "0". . Further, when the key data KTDM applied to the shift control input is "1", one shift operation is performed in synchronization with the fall of the pulse obtained by inverting the system clock pulse φ from "1" to "0". Therefore, "1" is set in the first stage of the shift register 20 at the beginning of one scan cycle by the scan start timing signal SY1 or SY2, and each time a pressed key is detected as the scan progresses (the pressed key is Each time the key scanning timing ends, the set single "1" is shifted to the next stage in sequence. Since key scanning is performed from the bass side, when the scanning timing of the seventh pressed key counting from the bass side ends, data "1" is sent from the seventh stage, and all stages of the shift register 20 become "0". Become. The key range detection circuit 15 uses the output of the shift register 20 and the key data KTDM to detect whether three pressed keys exist within a range not exceeding one octave. When the key data KTDM of the eighth or subsequent key pressed from the bass side appears, the outputs of all stages of the shift register 20 become "0", so the detection circuit 15 does not actually operate. This is because, in this example, it is assumed that the maximum number of keys pressed simultaneously on the keyboard 11 is seven.
Therefore, if the maximum number of simultaneously pressed keys is assumed to be 8 or more, the number of stages of the shift register 20 may be appropriately increased to 8 or more.

Output signal of each stage of shift register 20
SQ1 to SQ7 are input to AND circuits 21 to 27, respectively. Key data KTDM is applied to other inputs of AND circuits 21 to 27. The AND circuits 21 to 27 are for selecting the key data KTDM of the first to seventh pressed keys counting from the bass side, respectively. Key data corresponding to the scanning timing of the first pressed key counting from the bass side
When KTDM becomes “1”, “1” is held in the first stage of the shift register 20,
When the first stage output signal SQ1 and the key data KTDM both become "1", the condition of the AND circuit 21 is satisfied. Therefore, the key data of the first pressed key counting from the bass side (hereinafter referred to as the lowest note)
Corresponding to KTDM, the output of the AND circuit 21 becomes "1". When the key scanning timing of the lowest note ends, the data "1" in the shift register 20 is shifted from the first stage to the second stage.
As a result, the second stage output signal SQ2 becomes "1", and the AND circuit 22 becomes operable. Therefore, when the key data KTDM becomes 1'' in response to the scan timing of the second pressed key (hereinafter referred to as the 2nd bass note) counted from the bass side, ``1'' is output from the AND circuit 22. When the key scanning timing of the second bass note ends, the shift register 2
Data "1" in 0 is shifted from the second stage to the third stage, and the third stage output signal SQ3 becomes "1". As a result, the AND circuit 23 becomes operational, and when the key data KTDM becomes "1" corresponding to the scan timing of the third pressed key counting from the bass side (hereinafter referred to as the third bass note), the AND circuit 23 becomes operable. “1” is output from the circuit 23.
Similarly, "1" is sequentially outputted from each AND circuit 24 to 27 in response to the scan timing of the fourth to seventh pressed keys (hereinafter referred to as the fourth to seventh bass keys) counting from the bass side. .

The outputs of the AND circuits 21 to 27 are input to pulse extension circuits 28 to 33, respectively, and their pulse widths are extended. The pulse extension circuit 28 consists of an 11-stage/1-bit shift register 34 whose shift is controlled by the system clock pulse φ, and an OR circuit 35 inputting the outputs of all stages of the shift register 4. By sequentially shifting "1" output from the circuit 21 from the first stage to the eleventh stage of the shift register 34 according to the clock pulse φ, the AND circuit 2
A pulse with an 11-bit time width that rises with a delay of 1 bit time from the rise of the output of 1 is obtained from the OR circuit 35. Other pulse extension circuit 2
9 to 33 also have the same configuration as the circuit 28. The pulse width for 11 bit time is the key data for 11 keys.
Compatible with KTDM time width. Therefore, when "1" is output from the AND circuits 21 to 27 in response to the scanning timing of a certain pressed key, the difference is less than one octave on the treble side of the pressed key from the scanning timing of a key that is a semitone above the pressed key. During the key scan timing of
The outputs PE1 to PE6 of the pulse extension circuits 28 to 33 corresponding to the AND circuits 21 to 27 become "1".

For example, if keys G2, C3, and E3 are pressed nearby, and key D5 is pressed away from them, as shown in Figure 4, these pressed keys G2,
The key data KTDM becomes "1" corresponding to the scanning timings of C3, E3, and D5, respectively. in this case,,
As shown in the figure, during the period from 1 bit time after the scan timing of the pressed key G2 (the scan timing of G#2) to 11 bit times after the scan timing of the pressed key G2 (the scan timing of the key F#3), the pulse extension circuit 28
The output PE1 becomes “1”. Similarly, the output PE2 of the pulse extension circuit 29 becomes "1" from 1 bit time after the scanning timing of the pressed key C3, which is the second low tone, to 11 bit times after the scanning timing of the pressed key E3, which is the third low tone. The output PE3 of the pulse extension circuit 30 becomes "1" from 1 bit time to 11 bit time, and the output PE3 of the pulse extension circuit 30 becomes "1" from 1 bit time after the scanning timing of the pressed key D5, which is the fourth low tone, to 11 bit time after.
The output PE4 of 1 becomes "1". As can be seen from this example, the output signals PE1 to PE6 of the respective pulse extension circuits 28 to 33 become "1" corresponding to the key scanning section of less than one octave on the treble side of each of the lowest to sixth bass notes.

The AND circuit 36 is a circuit for determining whether or not there are three pressed keys including the lowest note within one octave on the treble side from the lowest note. For this purpose, the outputs of the pulse extension circuits 28 and 29
The outputs of PE1, PE2 and the AND circuit 23 are input to the AND circuit 36. The AND circuit 36 is made operable by the output PE1 of the pulse extension circuit 28 in response to a key scanning section of less than one octave on the treble side of the lowest note, and during this period the key data KTDM corresponding to the second and third bass notes is transmitted. Only when this occurs, the condition of the AND circuit 36 is satisfied. In other words, the key data corresponding to the second bass tone
When KTDM occurs, pulse extension circuit 2
When the output PE2 of 9 becomes "1" and the key data KTDM corresponding to the third bass tone is generated, the output of the AND circuit 23 becomes "1" and the output of the AND circuit 3 becomes "1".
Condition 6 is satisfied. In the case of FIG. 4, the second bass key C3 and the third bass key E3 belong to a range less than one octave on the treble side of the lowest key G2, so the condition of the AND circuit 36 is satisfied, Third
The output P1 of the AND circuit 36 becomes "1" at the scanning timing of the low tone key E3. If the second bass note or the third bass note does not belong to a range less than one octave on the treble side of the lowest note, the pulse extension circuit 28 output PE1
falls to "0", and the condition of the AND circuit 36 is not satisfied. In that case (if the conditions of the AND circuit 36 are not satisfied, that is, if the output P1 does not become "1"), the lowest tone, the second bass tone and the third
Bass means no nearby pressure.

The AND circuits 37 to 40 are connected to the second to fifth bass tones.
This circuit is for determining whether or not there are three pressed keys including the second to fifth bass tones within one octave range on the treble side from each of the bass tones. That is, the AND circuit 37 receives the outputs of the pulse extension circuits 29 and 30 regarding the second and third bass tones.
AND circuit 24 regarding PE2 and PE3 and the 4th bass
Similarly, the output of the pulse extension circuit 3 is input.
Outputs 0 to 33 PE3 to PE6 and AND circuit 25
The outputs of the AND circuits 38 to 27 are sequentially lowered and input to the AND circuits 38 to 40, respectively. With this configuration, when the second bass, third bass, and fourth bass exist within one octave range, the AND circuit 3
If the output P2 of the AND circuit 38 becomes "1" and the third bass, fourth bass, and fifth bass exist within one octave range, the output P3 of the AND circuit 38 becomes "1", and the fourth bass, the fifth bass In the case that the 5th bass and 6th bass exist within the 1 octave range, the output P4 of the AND circuit 39 becomes "1", and the 5th and 6th bass
If the bass and the seventh bass exist within one octave range, the output P5 of the AND circuit 40 is “1”
becomes.

Outputs P1 to P5 of each AND circuit 36 to 40
becomes "1" at the timing of the highest note among the three pressed keys existing within one octave range.
In the case of the example shown in FIG. 4, the output P1 of the AND circuit 36 becomes "1" at the scanning timing of the key E3, which is the highest note among the pressed keys G2, C3, and E3. Furthermore, at the scanning timing of key D5, which is the fourth bass, the pulse extension circuits 29 and 30 regarding the second and third bass
Since the outputs PE2 and PE3 of the
P2 does not become "1".

Outputs P1 to P5 of the AND circuits 36 to 40 are input to a shift register 42 via an OR circuit 41. The shift register 42 has 12 stages/1 bit and is shift-controlled by the system clock pulse φ. The outputs of all stages of this shift register 42 are input to an OR circuit 43, and the output of the OR circuit 43 is a key area detection signal in which a predetermined number of pressed keys exist.
It is output from the key range detection circuit 15 as 3KD*.
Signal 3KD* is the output of AND circuits 36 to 40
It becomes "1" from 1 bit time after the timing when P1 to P5 become "1" (that is, the scanning timing of the highest note among the three keys pressed in the vicinity) until 12 bit times after. In the case of Fig. 4, the output P1 of the AND circuit 36 becomes "1" at the scanning timing of the key E3, so the signal 3KD* is output from the scanning timing of the key F3 one bit time later.
It becomes "1" for 12 bit times until the scanning timing of key E4 after 12 bit times.

The 12-bit time period during which the signal 3KD* is "1" indicates a one-octave key range in which a predetermined number (3 keys) or more of pressed keys are present. In other words, a 12-bit time period corresponds to a scanning period for one octave of keys (12 keys), and the key scan timing depends on which key's scanning timing this 12-bit time period starts and ends at. area is identified. By the way, this signal 3KD* is
Since this occurs during the 12-bit time immediately after the timing of the highest note of the three pressed keys existing in a range of less than one octave, one octave worth of key data KTDM including the three pressed keys in the vicinity is sent to the multiplexer 12. It is 12 bits later than the timing output from (Figure 1). Therefore, the key data KTDM supplied from the multiplexer 12 (FIG. 1) to the discriminator 14 is delayed by 12 bits in the shift register 44, and the key data KTDM* synchronized with the predetermined number of pressed keys existing key area detection signal 3KD* is selected. The signal is output from the shift register 44. As shown in Figure 4, 12
In the bit time delayed key data KTDM*, the three keys pressed nearby (G2, C3,
The timing at which data in E3) appears is determined by the signal
It is synchronized with the one octave period when 3KD* is "1".

The signal 3KD* and the key data KTDM* are input to an AND circuit 45 in the chord formation detection circuit 16. The remaining inputs of the AND circuit 45 receive the first cycle key scanning section signal HA* (FIG. 2). As mentioned above, this signal HA* indicates a period obtained by delaying the key scanning period of 49 bit time during which the key data KTDM from the lowest key C2 to the highest key C6 is output in the first cycle by 12 bit times. Key C2~ in key data KTDM* with a 12-bit time delay from data KTDM
It is synchronized with the timing of key C6. Therefore, the AND circuit 45 inputs all the key data KTDM* (when the signal 3KD* is "1") in the key range where a predetermined number or more of pressed keys exist in the first cycle (when the signal HA* is "1"). ”). In the case of FIG. 4, the key data KTDM* of the three keys (G2, C3, E3) pressed nearby pass through the AND circuit 45, and the key data KTDM* of the key D5 pressed far away from them passes through the AND circuit 45. is AND circuit 4
Blocked by 5.

The key data KTDM* of a partial key range for one octave that has passed through the AND circuit 45 is input to the shift register 47 via the OR circuit 46. The shift register 47 has 12 stages/1 bit and is shift-controlled by the system clock pulse φ. Therefore, from the OR circuit 46 to the shift register 4
One octave worth of key data inputted to 7 is sequentially shifted in synchronization with the scanning timing according to the clock pulse φ. 12th shift register 47
The output of the stage is returned to the first stage via an OR circuit 46. This results in
One octave of key data (KTDM*) selected by the AND circuit 45 is circulated within the shift register 47 and stored and held. Therefore, OR circuit 46
Data input to shift register 47 from
As shown in Figure 4, 3KEY* has the same note timing (note name G,
It becomes "1" repeatedly at timings C and E). That is, the output data 3KEY* of the OR circuit 46 indicates the pitch names (G, C, E) of the three keys (G2, C3, E3) pressed nearby.

Output of the 12th stage of shift register 47
3KEY** is the output 3KEY* of the OR circuit 46 delayed by 12 bits, but indicates the same note name, and the note name is synchronized with the note name at the key scanning timing. In the chord establishment detection circuit 16,
The output of the 12th stage of this shift register 47
Using 3KEY** as key press data corresponding to the root note (1 degree), it is detected whether a chord is established between it and other key press data. Key data KTDM
(KTDM*) is generated in order from the bass key, so if the 12th stage of the shift register 47 is regarded as the root note (1 degree), the data stored in the 11th stage is a semitone of the root note. It corresponds to the upper or minor second degree (2 ^b ). Similarly, shift register 47
The 10th stage to the first stage contain data of pitch names having intervals of major 2nd (2) to major 7th (7) relative to the root note. Incidentally, the shift register 47 is reset by the signal SY1* (see FIG. 2) at the start of scanning in the first cycle. The key data KTDM uses the signal SY1*, which is the first cycle scan start timing signal SY1 delayed by 12 bits.
This is to synchronize with *.

The AND circuit 48 is for detecting whether or not a major chord is established.
The outputs of the stages corresponding to the 7's 1st (1), the major 3rd (3) and the perfect 5th (5) are input. AND circuit 49
is for detecting whether a minor chord is established or not, and the outputs of the stages corresponding to the 1st (1), minor 3rd (3 ^b ), and perfect 5th (5) of the shift register 47 are input. be done. The AND circuit 50 is for detecting whether a seventh chord is established or not, and is used for stages corresponding to the first degree (1), major third (3), and minor seventh (7 ^b ) of the shift register 47. Output is input. The AND circuit 51 is for detecting whether or not a minor seventh chord is established.
1st (1) and minor 3rd (3 ^b ) of shift register 47
and the output of the stage corresponding to the minor seventh (7 ^b ) is input. The outputs of the AND circuits 48 to 51 are input to OR circuits 53 to 56 via a priority circuit 52.

The outputs of all the AND circuits 48 to 51 via the priority circuit 52 are input to the OR circuit 53. The output of this OR circuit 53 is the chord establishment signal CH
used as. Mejiya, Minor, Seventh,
Alternatively, when any chord of the minus seventh is established, the signal CH becomes "1". OR circuit 54
The outputs of AND circuits 48 and 50 via priority circuit 52 are input to . The major third selection signal 3M output from this OR circuit 54 becomes "1" when a major chord or a seventh chord is established.
Indicates that a major third should be selected as the third. The outputs of the AND circuits 49 and 51 via the priority circuit 52 are input to the OR circuit 55 . Minor third selection signal 3m output from this OR circuit 55
becomes "1" when a minor chord or a minor seventh chord is established, indicating that a minor third should be selected as the third. The outputs of the AND circuits 50 and 51 via the priority circuit 52 are input to the OR circuit 56 . The minor seventh selection signal 7D output from this OR circuit 56 becomes "1" when a seventh or a minor seventh chord is established. The priority circuit 52 is a circuit for preferentially selecting only one chord when a plurality of chords are established at the same time (when "1" is output from a plurality of AND circuits 48 to 51 at the same time). That is, when a plurality of chords having the same root note are detected, the priority circuit 52 selects one of them preferentially. The priority order is: Major → Minor → Seventh → Minor Seventh (AND circuit 48 → 49 → 5
0→51).

The chord establishment signal CH is applied to an AND circuit 57 and also to a delay flip-flop 59 via an OR circuit 58. delay flip-flop 5
The output of 9 is self-held via an AND circuit 60 and an OR circuit 58. Further, a signal obtained by inverting the output of the delay flip-flop 59 by an inverter 61 is applied to the AND circuit 57. A signal obtained by inverting the timing signal SY1** (see FIG. 2) by an inverter 62 is applied to the other input of the AND circuit 60. Delay flip-flop 59 is cleared by signal SY1** at the beginning of the first cycle of scanning. 1st cycle scan start timing signal SY1
The reason why the signal SY1** delayed by 24 bit time is used is that the timing of the chord formation signal CH is delayed by 24 bit time than the timing of the key data KTDM. In other words, there is a 12-bit time delay in shift register 42, and shift register 4
7 causes an additional 12 bit time delay.

At the beginning of the first cycle, the delay flip-flop 5
The output of the inverter 61 is "0", and the AND circuit 57 is enabled to operate due to the output "1" of the inverter 61. Therefore, the output of the AND circuit 57 becomes "1" at the timing when the chord establishment signal CH is first generated. Since "1" is stored in the delay flip-flop 59 based on this first chord formation signal CH, the AND circuit 57 becomes inoperable thereafter. Therefore, if the chord establishment signal CH occurs twice or more, the second and subsequent signals CH are blocked by the AND circuit 57. The output of the AND circuit 57 is supplied to the chord constituent note extraction circuit 17 as a chord establishment detection signal CHLD**. This chord formation detection signal
CHLD** is used only when a chord formation is detected for the first time in the first cycle (first chord formation signal
(corresponding to CH) becomes “1”.

In the chord constituent note extraction circuit 17, the AND circuits 63 to 67 are for extracting only the data of the constituent notes of the chord whose establishment has been detected by the chord establishment detection circuit 16 from the required stages of the shift register 47. The shift register 68 is for creating time-division multiplexed chord constituent note data CHND** corresponding to the note names based on the chord constituent note data taken out by the AND circuits 63 to 67. One input of each AND circuit 63 to 67 corresponds to 1st (1), minor 3rd ( ^3b ), major 3rd (3), perfect 5th (5), and minor 7th ( ^7b ). The outputs of the 12th stage, 9th stage, 8th stage, 5th stage, and 2nd stage of the shift register 47 are respectively added. The chord formation signal CH is applied to other inputs of the AND circuits 63 and 66.
The other input of the AND circuit 64 is a minor third selection signal.
3m is added. A major third selection signal 3M is applied to the other input of the AND circuit 65. A minor seventh selection signal 7D is applied to the other input of the AND circuit 67.

The shift register 68 has 12 stages/1 bit and is shift-controlled by the system clock pulse φ. The outputs of the AND circuits 63 to 67 are input to the same stages of the shift register 68 (i.e., the 12th stage, the 9th stage, the 8th stage, the 5th stage, and the 2nd stage) as the stages from which the data is taken out from the shift register 47, respectively. be done. A timing signal SY1** (FIG. 2) is applied to the reset input R of the shift register 68, so that it is reset at the start of scanning in the first cycle. Signal SY1 that is 24 bit time delayed from the first cycle scan start timing signal SY1
The reason for using ** is that the shift register 47
This is because the timing of the data that appears in the 12th stage is 24 bits later than the timing of the key data KTDM. The set control input S of the shift register 68 receives a chord formation detection signal CHLD*.
* is added. When the signal CHLD** applied to the set control input S becomes "1", the shift register 68 enters the set mode and takes in the data input in parallel to each stage. As mentioned above, data from the AND circuits 63 to 67 is taken into the 12th stage, 9th stage, 8th stage, 5th stage, and 2nd stage, but "0" is taken into the other stages. . Further, the output of the 12th stage of the shift register 68 is fed back to the first stage. Therefore, the data taken in at the timing when the signal CHLD** is generated is sequentially shifted in accordance with the clock pulse φ and transferred to the shift register 68.
circulate within.

When a chord is established, the AND circuits 63 and 66 are enabled by the signal CH, which corresponds to the 1st (1) and perfect 5th (5) contained in the 12th and 5th stages of the shift register 47. The data is taken into the 12th stage and the 5th stage of the shift register 68, respectively. At the same time, the chord formed is a major chord (including the seventh chord) or a minor chord (including the minor seventh chord)
Either the AND circuit 64 or 65 is enabled by the signal 3m or 3M depending on
The ninth stage or the eighth stage of the shift register 47
The data corresponding to the minor third (3 ^b ) or major third (3) entered in the stage is taken into the ninth or eighth stage of the shift register 68 . At the same time, if the established chord is a seventh chord or a minor seventh chord, the AND circuit 67 is enabled by the signal 7D, and the chord corresponding to the minor seventh (7 ^b ) entered in the second stage of the shift register 47 is activated. Data is loaded into the second stage of shift register 68.

In the example of FIG. 4, the 12th shift register 47
Every time "1" appears as the stage output 3KEY** at the timing of note name C, the condition of the AND circuit 48 is satisfied, and the chord establishment signal CH and the major third selection signal 3M are generated. In this example, in the shift register 47, three data “1”s are circulated at timings corresponding to the note names (G, C, E) of the three keys (G2, C3, E3) pressed nearby. Therefore, when data "1" regarding pitch name C enters the 12th stage, data "1" regarding pitch name E, which is a major third above it, enters the 8th stage corresponding to major third (3). The data "1" related to the pitch name G above the perfect fifth is entered in the fifth stage corresponding to the perfect fifth (5). Therefore, the conditions for the AND circuit 48 inputting the outputs of these stages are satisfied,
Signals CH and 3M become "1". In other words, it is detected that a major chord is established. Corresponding to the first generated chord formation signal CH, a chord formation detection signal CHLD** is generated as shown in FIG.
The outputs "1" of the 12th stage, 8th stage, and 5th stage of the shift register 47 are transferred to the 12th stage of the shift register 68 via the AND circuits 63, 65, and 66, which are enabled by the signals CH and 3M. , are taken into the eighth stage and the fifth stage, respectively.

The "1" taken into the 12th stage of the shift register 68 is immediately output from the 12th stage. The output of this twelfth stage is input to the AND circuit 69 as chord constituent tone note data CHND**. Therefore, the chord constituent note note data CHND output from the 12th stage of the shift register 68
** indicates the chord formation detection signal as shown in Figure 4.
It first becomes "1" at the note timing of the root note (timing of note C) where CHLD** occurs.
Shift register 6 at the timing of signal CHLD**
The data “1” related to the major third taken into the 8th stage of 8 becomes the 12th data 4 bit times later.
The output CHND* of the 12th stage is shifted to the note name E, which is 4 bit times after the timing of note name C, which is the root note.
* becomes “1”. Furthermore, the data "1" related to the perfect fifth, which was taken into the fifth stage of the shift register 68 at the timing of the signal CHLD**, has been shifted to the 12th stage seven bit times later, and the data "1", which is the root note, has been shifted to the 12th stage. The output CHND** of the 12th stage becomes "1" at the timing of note name G, which is 7 bit times after the note name C timing.
Thereafter, the chord constituent tone note data CHND** is repeatedly set to "1" at the timing of the note names C, E, and G that constitute the chord.

The AND circuit 69 in the chord constituent note extraction circuit 17 receives the chord constituent note note data CHND** and the second cycle key scanning section signal HB** (see Fig. 2).
and a 12-stage/1-bit shift register 70
A signal 3KD** obtained by delaying the key area detection signal 3KD* with a predetermined number of pressed keys by 12 bits is input.
The reason for using the signal 3KD**, which is obtained by delaying the signal 3KD* by 12 bit time in the shift register 70, is that the shift register 47 of the chord formation detection circuit 16
Due to the 12-bit time delay,
This is to synchronize with the timing of this data CHND**, since the generation timing of the chord constituent note data CHND** is delayed by 12 bits from the timing of the signal 3KD*. For the same reason, the key scanning interval of the second cycle (keys C2 to C6
The signal HB** indicating the scanning timing up to
(12 bit time from KTDM* timing)
Running late. In the second cycle in which this signal HB** is generated, as a result of the above-mentioned chord detection performed in the first cycle, chord constituent note note data is generated corresponding to the timing of each note name of the chord constituent notes.
CHND** occurs repeatedly. For example, if chord constituent note data CHND** is generated at the timing of note names C, E, and G as shown in Figure 4,
As shown in FIG. 5, in the second cycle, the chord constituent tone note data CHND** is repeatedly set to "1" corresponding to the timing of the pitch names C, E, and G. FIG. 5 shows an example of the operation in the second cycle when key data KTDM is generated as shown in FIG. Note that one scanning cycle is 60 bit times, so the data is repeated every 12 bit times.
The pitch name timing of CHND** is always synchronized with the pitch name timing in the first cycle and second cycle key scanning.

The predetermined number of pressed keys existing key area detection circuit 15 operates in the same manner as the first cycle in the second cycle, so that the predetermined number of pressed keys existing key area detection signal 3KD* is obtained in the second cycle as well (the fifth (see figure). Similar to the first cycle (see Figure 4), the second
In the cycle, one octave of keys including the three keys G2, C3, and E3 (F2
12 corresponding to the interval of key data KTDM* which is delayed by 12 bit time from the key data KTDM of ~E3).
A signal of 3KD* is generated with a bit time width. In the second cycle (when the signal HB** is "1"), when the signal 3KD**, which is the signal 3KD* delayed by 12 bits, is generated, the AND circuit 69 becomes operational. Therefore, the signal 3KD** is generated12
Chord composition note data only between bit times
CHND** passes through an AND circuit 69 and is output as a chord constituent tone discrimination signal CHKD**. In this way, the chord constituent note discrimination signal CHKD** corresponds to the scanning timing of the chord constituent notes that are actually pressed.
is generated.

The chord constituent tone discrimination signal CHKD** is the discrimination means 14
is input to the AND circuit 71. AND circuit 72
A signal obtained by inverting the signal CHKD** by an inverter 73 is input to the inverter 73. Furthermore, key data KTDM** obtained by further delaying key data KTDM* by 12 bits in the shift register 74 is input to AND circuits 71 and 72, respectively. key data
The reason why KTDM* is delayed by 12 bit time is to synchronize the timing of the key area detection signal 3KD** with a predetermined number of pressed keys and the key data KTDM**. The key data KTDM** delayed by 24 bits from the key data KTDM is synchronized with the signal 3KD** as shown in FIG. That is,
In the example shown in Fig. 5, when a key range detection signal 3KD** indicating a one-octave key range from keys F2 to E3, in which a predetermined number or more of keys are pressed, is generated, the key F2 is generated as key data KTDM**. The scan results from to E3 appear. Therefore, the chord constituent tone discrimination signal CHKD
When ** is "1", the key data KTDM** (keys G2, C3, E3 in the case of Fig. 5) indicating the pressed keys that make up the chord becomes "1", and these chord constituent keys ( G2, C3, E3) key data KTDM**
Only the data AKD is selected by the AND circuit 71 and discriminated as accompaniment key data AKD.

A second cycle key scanning period signal HB** (see FIG. 2) is applied to the remaining inputs of the AND circuit 72. As a result, the AND circuit 72 uses the key data obtained by scanning in the second cycle.
KTDM** other than chord constituent tones (signals)
Key data when CHKD** is “0”)
Select all KTDM** and distinguish it as melody key data MKD. In the case of FIG. 5, the key data KTDM** of the pressed key D5 is output as the melody key data MKD. All keys other than the keys that make up the chord are distinguished as melody notes, so even if a melody key is pressed near a chord-constituting key (for example, within the same octave), the melody note specification key and the accompaniment note (chord) ) can be distinguished from the specified key. Note that in the first cycle, melody key data MKD and accompaniment key data AKD are not generated. This is because the AND circuits 69, 71, and 72 become inoperable when the second cycle key scanning section signal HB** becomes "0".

The melody key data MKD output from the AND circuit 72 is input to the melody tone forming circuit 75 (FIG. 1), and the accompaniment key data AKD output from the AND circuit 71 is input to the accompaniment tone forming circuit 76 (first (Figure). The melody musical tone forming circuit 75 is a circuit that forms a musical tone signal having a pitch corresponding to the pressed key indicated by the melody key data MKD in accordance with a melody musical tone formation mode. Factors that determine the manner in which musical tones are formed include timbre, volume, pitch, envelope shape, and the like, and the quality of melody tones is characterized by these factors. Furthermore, a tone selection means 77 allows any desired melody tone to be selected.

The accompaniment tone forming circuit 76 generates accompaniment key data.
This circuit forms a musical tone signal of a pitch corresponding to the pressed key indicated by AKD in accordance with an accompaniment musical tone formation mode. The manner in which musical tones are formed for accompaniment is different from the manner in which musical tones are formed for melody. The expression "different in form" refers to a difference in one or more of the factors that determine the form of musical sound formation, such as timbre, volume, pitch, envelope shape, or foot system. A timbre selection means 78 is provided in association with the accompaniment musical tone forming circuit 76, so that an accompaniment tone can be arbitrarily selected. Furthermore, it is more preferable that the accompaniment tone forming circuit 76 has an automatic accompaniment function. Note that the melody key data MKD and the accompaniment key data AKD are the key data output from the multiplexer 12.
Since it is time division multiplexed data similar to KTDM, this dynamic key data is used in the melody musical tone forming circuit 75 and the accompaniment musical tone forming circuit 76.
It shall include demultiplexing means for demodulating static key press information from MKD and AKD. For this demultiplexing, a system clock pulse φ synchronized with key scanning, a second cycle key scanning interval signal HB** and a timing signal SY2** are supplied to tone forming circuits 75 and 76. signal
The reason for using HB** is that when this signal HB** is generated, valid key data MKD and
Because AKD is given. Since such demultiplexing means are well known, no particular details will be given.

The automatic accompaniment pattern generator 79 is a circuit that generates various automatic performance patterns such as an automatic rhythm pattern, an automatic bass pattern, an automatic chord generation pattern, or an automatic arpeggio pattern. When the automatic performance mode is selected, the accompaniment musical tone forming circuit 76 generates an automatic bass tone, chord, automatic arpeggio tone, and even automatic rhythm based on the automatic performance pattern from the pattern generator 79 and the accompaniment key data AKD. Automatically generates automatic accompaniment sounds such as notes. The musical tone signals of the melody tone and accompaniment tone formed by the melody musical tone forming circuit 75 and the accompaniment musical tone forming circuit 76 are applied to the sound system 80 and are generated.

By the way, human key press operations are not as precise as high-speed digital systems, and even if you intend to press multiple keys that make up a chord at the same time, there is usually some variation in the timing at which each key is pressed. . Therefore, if the system is configured to respond immediately to key presses, a chord may not be detected temporarily when the key is first pressed, and a part of the key pressed with the intention of accompaniment may temporarily become a melody note. This causes the inconvenience of being pronounced as In order to prevent this inconvenience from occurring, the multiplexer 12 includes a waiting time setting means (not shown), and instead of outputting the multiplexed key data KTDM in response to a key press operation immediately, The key data KTDM may be output after waiting for the key data KTDM of a plurality of pressed keys to stably appear within this waiting time.

FIG. 6 is a block diagram of the overall configuration of an electronic musical instrument showing another embodiment of the present invention, and even when one or more keys that do not constitute a chord are pressed for accompaniment performance, those pressed keys are used for accompaniment performance. It is characterized by being able to be differentiated into groups.
To this end, in the example shown in FIG. 6, the lowest one-octave key range (key range from keys C2 to B2) on the keyboard 81 is reserved as an accompaniment-only key range. Keys pressed in the accompaniment-only range are unconditionally classified into the accompaniment group, and if a chord is composed of multiple keys pressed near the accompaniment-only range, it is considered to be outside the accompaniment-only range. However, the keys in the keyboard range that include those chord-constituting keys are classified into accompaniment groups.

In FIG. 6, the keyboard 81 is the keyboard 11 in FIG.
Similarly, it has 49 keys from C2 to C6.
Multiplexer 82 is multiplexer 1 in FIG.
Similarly to 2, the keys are scanned in order from the bass side to output time division multiplexed key data KTDM. The melody musical tone forming circuit 83, the accompaniment musical tone forming circuit 84, the tone selection means 85, 86, the automatic performance pattern generator 87, and the sound system 88 perform the same functions as the circuits 75 to 80 with the same names in FIG. It is something. In addition, in FIG. 6, as in FIG. 1, two cycles of the key scanning cycle are used for chord detection and discrimination. In the first cycle (first cycle), the chord detecting means 89 performs chord detection processing, and in the next cycle (second cycle), the discriminating means 90 performs discrimination processing. A timing signal generator 91 generates a system clock pulse φ and timing signals SY1, SY2, HA, HB, Y12, Y24 for controlling various operations in the first cycle and the second cycle.
occurs as shown in FIG.

One scan cycle consists of 60 time slots (60 bit times), the first cycle scan start timing signal SY1 becomes "1" at the first timing of the first cycle (time slot 60), and the second cycle scan start timing signal SY2 becomes "1". It becomes "1" at the first timing (time slot 60) of the second cycle. In each scanning cycle, scanning timings from the lowest key C2 to the highest key C6 are assigned to time slots 1 to 49. The first cycle key scanning interval signal HA is generated corresponding to the scanning timing from keys C2 to C6 in the first cycle, and the second cycle key scanning interval signal HB is generated corresponding to the scanning timing from keys C2 to C6 in the second cycle. Generated according to timing. The minimum one-octave signal Y12 becomes "1" corresponding to the scanning period from the lowest key C2 to the key B2, which is the lowest one-octave key range, that is, the accompaniment-only key range. Minimum 2 octave signal
Y24 becomes "1" corresponding to the scanning period of the lowest two-octave key range from the lowest key C2 to the key B3.

The time-division multiplexed key data KTDM output from the multiplexer 82 is applied to the AND circuit 92 in the chord detection means 89, and is also applied to the AND circuit 92 in the chord detection means 89.
It is added to the AND circuit 93 in 0. The other input of the AND circuit 92 is the first cycle key scanning section signal.
HA is applied, and the second cycle key scanning period signal HB is applied to the other input of the AND circuit 93.
In the chord detection means 89, the key data KTDM of the first cycle is taken in by the AND circuit 92, and chord detection processing is performed in the first cycle.
Further, in the discrimination means 90, the key data KTDM of the second cycle is taken in by the AND circuit 93, and the key data KTDM is generated in the second cycle using the chord detection result in the previous first cycle.
Distinguish KTDM into melody key data MKD or accompaniment key data AKD.

The key data KTDM passed through the AND circuit 93 in the second cycle is transferred to the AND circuits 94 and 95.
are input respectively. The output of the OR circuit 96 is added to the other input of the AND circuit 94.
A signal obtained by inverting the output of the OR circuit 96 by an inverter 97 is applied to the other input of the circuit 5. OR circuit 9
At least one octave signal Y12 (see FIG. 7) is applied to one input of 6. Therefore, when the at least one octave signal Y12 is "1", the AND circuit 94 becomes operational, and the key data KTDM of keys C2 to B2 belonging to the at least one octave key range (that is, the accompaniment-only key range) is unconditionally It passes through the AND circuit 94 and is output as accompaniment key data AKD.

Key data for a range other than at least one octave
KTDM generates accompaniment key data according to the output of the AND circuit 98 which is added to other inputs of the OR circuit 96.
Distinguished as either AKD or melody key data MKD. The output of the key range control circuit 99 and the break contact side output (FC) of the single finger mode selection switch SF-SW are added to the AND circuit 98. When selecting single finger mode (SF), switch SF-SW to the make contact side and set the break contact output (FC) to "0". Therefore, single finger mode
When SF is selected, the AND circuit 98 becomes inoperable, and the output of the key range control circuit 99 (ie, the chord detection result by the chord detection means 89) is not used by the discrimination means 90. Single finger mode
In the case of SF, only key data KTDM of at least one octave key range (accompaniment-only key range) is discriminated as accompaniment key data AKD by signal Y12.
When key data KTDM of other key ranges (keys C3 to C6) is generated, the output of the OR circuit 96 becomes "0", which enables the AND circuit 95 to operate, and all keys C3 other than the accompaniment-only key range are generated. -C6 key data KTDM passes through the AND circuit 95 and is output as melody key data MKD. Single finger mode SF is a mode in which only a desired root note is pressed as an accompaniment note designation key, and chord constituent notes are automatically formed based on this root note and a separately selected chord type. Therefore, in the case of single-finger mode SF, it is only necessary to press one key that specifies the desired root note in the at least one octave key range that is the accompaniment-only key range, and the key data KTDM of this root note specification key is The accompaniment musical tone forming circuit 84 passes through the circuit 94 and becomes accompaniment key data AKD.
given to.

Single finger mode selection switch SF-SW
A single finger mode signal SF output from the make contact of is applied to the accompaniment tone forming circuit 84. In the accompaniment musical tone forming circuit 84, when the single finger mode signal SF is "1", that is, when the single finger mode is selected, the accompaniment tone forming circuit 84 generates the root note indicated by the accompaniment key data AKD and the appropriate selection. A musical tone signal of a plurality of tones constituting a chord is automatically formed based on a chord type selection signal (not shown) given from a means (not shown), and a chord sounding timing pattern given from a pattern generator 87 is generated. Therefore, it has a function to automatically generate sounds.

Single finger mode selection switch SF-SW
If is set on the break contact side as shown in the figure, it indicates the finger code mode FC. What is Finguard Code Mode FC?
In this mode, all constituent notes of a desired accompaniment note (chord) are actually pressed. In the case of the finger code mode FC, the break contact side output FC of the switch SF-SW becomes "1", and the AND circuit 98 becomes operable. In the following description, it is assumed that "1" is supplied to the AND circuit 98 from the break contact side output FC of the switch SF-SW.

The chord detecting means 89 detects chords in one of "A mode" and "B mode". "A mode" is a mode that requires that at least one of the pressed keys that is the target of chord detection belongs to the accompaniment-only key area, and "B mode" is a mode that requires the pressed keys that are the target of chord detection. In this mode, it is acceptable as long as the key belongs somewhere within a minimum two-octave key range (keys C2 to B3) consisting of an accompaniment-only key range and a one-octave key range on the treble side.

When selecting "A mode", switch the chord detection mode selection switch 100 to the flip-flop 101 side as shown. The flip-flop 101 is reset by the signal SY1 at the start of scanning in the first cycle, and is set in the first cycle when it is detected that a key is pressed in at least one octave key range (accompaniment dedicated key range). . That is, the set input S of the flip-flop 101 is supplied with the output of the AND circuit 92 and the output of the AND circuit 102 to which the at least one octave signal Y12 (see FIG. 7) is input.
When the key data KTDM of the octave key range becomes "1", the flip-flop 101 is set.

The first cycle key data KTDM selected by the AND circuit 92 is also input to the AND circuit 103 . A minimum two-octave signal Y24 (see FIG. 7) is applied to the other input of the AND circuit 103.
This AND circuit 103 is for selecting key data (AKTDM) to be detected as a chord. The key range to be detected is the vicinity of the accompaniment-only key range, and in this example, a minimum two-octave key range (key range from keys C2 to B3) consisting of the accompaniment-only key range and the one-octave key range on the treble side. This is the key range for chord detection. Therefore, at least 2 octave signal Y24
At this timing, key data (AKTDM) belonging to at least a two-octave key range is selected.

Key data selected by AND circuit 103
AKTDM is input to AND circuit 104. The output of the chord detection mode selection switch 100 is applied to the other input of the AND circuit 104. In the case of "A mode", the output signal ARK of the flip-flop 101 is applied to the AND circuit 104 via the switch 100. The key data AKTDM output from the AND circuit 104 is the chord formation detection circuit 1
05 and the control input L of the latch circuit 111 of the key range control circuit 99.

In "A mode", if a key is pressed in the accompaniment-only area, the first key data KTDM
At the timing of (“1”), the flip-flop 101
is set, and its output signal ARK rises to "1". For example, as shown in columns A and C in Figure 7,
Assuming that G2, C3, E3, and D4 are pressed and the key data KTDM becomes (“1”) at their scanning timings, the output signal ARK of the flip-flop 101 becomes It rises to “1”. In addition, A・ in Figure 7
Column C shows an example of A mode and C mode. When the signal ARK becomes "1", the AND circuit 104 becomes operational, and the key data (AKTDM) in the minimum two-octave key range is selected by the AND circuit 104, and the key data AKTDM is selected by the AND circuit 104.
Key data AKTDM is generated in response to. still,
The key data AKTDM before the lowest pressed key is blocked by the AND circuit 104, but since their value is "0", the key data is virtually the same as the key data (AKTDM) of the lowest two-octave key range.
AKTDM is obtained from AND circuit 104. 7th
In the example in columns A and C in the diagram, the key data AKTDM is the key
It becomes “1” at the timing of G2, C3, and E3.

The chord formation detection circuit 105 is configured similarly to the chord formation detection circuit 16 shown in FIG. Key data AKTDM with minimum 2 octave key range is OR circuit 10
6 to a 12-stage/1-bit shift register 107, and circulates within the shift register 107 every 12 bits. This OR circuit 1
06 and the shift register 107 correspond to the OR circuit 46 and the shift register 47 in the chord formation detection circuit 16 in FIG. In addition, in FIG. 3, the shift register 47 receives the first cycle scan start timing signal.
It is reset by the signal SY1* which is SY1 delayed by 12 bits, but the shift register 1 in Fig. 6
07 is reset by the undelayed signal SY1. This is because the key data AKTDM input to the shift register 107 is undelayed data. The chord detection logic 108 to which the outputs of all stages of the shift register 107 are input is configured exactly the same as the logic consisting of the AND circuits 48 to 51, the priority circuit 52, and the OR circuit 53 in the chord formation detection circuit 16 shown in FIG. be done. That is, based on the state of each stage of the shift register 107, a major chord, a minor chord,
It detects whether a seventh chord or a minor seventh chord is established, and outputs a chord establishment signal CH when it is detected that any chord is established.

The chord establishment signal CH is applied to a set input S of a flip-flop 110 via an AND circuit 109. The other input of the AND circuit 109 is given the first cycle key scanning section signal HA, and the first
Only the chord formation signal CH generated in the cycle is selected. The reset input R of the flip-flop 110 receives the first cycle scan start timing signal.
SY1 is input and is reset at the beginning of the first cycle.

When it is detected that a chord is formed by pressing keys in a minimum two-octave range, a chord formation signal is generated.
CH is generated, and flip-flop 110 is set by this signal CH. This set state of flip-flop 110 is maintained until it is reset by signal SY1 at the beginning of the next first cycle. The output Q of the flip-flop 110 is input to AND circuits 112 and 113 in the key range control circuit 99 as a chord formation storage signal CHM. When a chord formation is detected, the chord formation storage signal CHM becomes "1" during the entire period of the second cycle from the chord detection point of the first cycle.

In the example shown in Figure 7, the key data AKTDM becomes "1" at the timing of keys G2, C3, and E3, so the key
When "1" taken into the shift register 107 at timing C3 is shifted to the 12th stage (that is, at the scanning timing of key C4), it is detected that a C major chord is established, and the chord establishment signal CH is detected. Generated (becomes “1”). Therefore, the chord establishment storage signal CHM remains "1" from the scanning timing of the key C4 in the first cycle to the end of the second cycle.

On the other hand, the counter 11 is used as the data input of the latch circuit 111 controlled by the key data AKTDM.
A count output of 4 is added. counter 1
14 is reset by the signal SY1 at the start of the first cycle scan, and thereafter increases the count value sequentially in accordance with the clock pulse φ. Therefore, starting from the scanning timing of the lowest key C2 in the first cycle, the count value of the counter 114 increases sequentially in synchronization with the progress of key scanning. The count value of this counter 114 represents the name of the key currently being scanned. The latch circuit 111 captures and stores the count value of the counter 114 when the key data AKTDM applied to the control input L is "1". The count value stored in this latch circuit 111 is updated every time the key data AKTDM becomes "1".
Finally, the key data AKTDM is “1”
The count value taken in at the timing when 0 is reached is stored and held in the latch circuit 111. That is,
The count value (binary coded signal) indicating the highest pressed key in the minimum two-octave key range is the latch circuit 1.
11.

In addition, in the "A mode", if there is no pressed key in the accompaniment-only keyboard range (minimum 1-octave key range), the output signal of the flip-flop 101
ARK does not rise to "1" forever, and the AND circuit 104 remains inoperable. Therefore, even if a key is pressed in the second octave range (keys C3 to B3), at least two octave ranges (keys C3 to B3) are pressed.
All of the key data (AKTDM) of C2 to B3) are blocked by the AND circuit 104, and no key data AKTDM that is the object of chord detection is generated. Therefore, chord detection becomes impossible, and the chord establishment memory signal
CHM remains at “0”. As mentioned below,
When the chord establishment memory signal CHM is "0", that is, when no chord can be detected, the key data KTDM for all keys (C3 to C6) other than the accompaniment dedicated key area
is identified as melody key data MKD.

When selecting "B mode", the chord detection mode selection switch 100 is switched to position B, which is opposite to that shown. As a result, "1" is always input to the AND circuit 104, and the key data (AKTDM) in the minimum two-octave key range is unconditionally input to the AND circuit 104.
Key data selected in step 4 and targeted for chord detection
Output as AKTDM. Therefore, in the case of "B mode", the second octave key range (keys C3 to B3)
Even if the keys are only pressed, these pressed keys are subject to chord detection.

The key range control circuit 99 controls the key range to be distinguished as an accompaniment group depending on one of the "C mode" and the "D mode". "C mode" is a mode in which the accompaniment group includes up to the highest pressed key in the key range that is the target of chord detection.
The "D mode" is a mode in which all keys in the accompaniment-only key range and a predetermined key range in its vicinity are included in the accompaniment group.

When selecting the "C mode", the key range movement selection switch 115 is switched to the flip-flop 116 side as shown. flipflop 116
The output of the AND circuit 113 is added to the set input S of the . The AND circuit 113 includes a second cycle scan start timing signal SY2 and a chord establishment memory signal.
CHM is added. The first cycle scan start timing signal SY1 is applied to the reset input R of the flip-flop 116 via the OR circuit 117, and the output of the comparator 118 is applied to the AND circuit 1.
19, delay flip-flop 120 and OR circuit 117. flipflop 1
16 is reset at the start of the first cycle scan by the signal SY1, and is reset at the start of the second cycle scan (signal SY2) on the condition that a chord is established (chord establishment memory signal CHM is "1"). is “1”). Therefore, as shown in columns A and C of FIG. 7, when a chord is established, the output signal AKRP of the flip-flop 116 rises to "1" at the beginning of the second cycle.

The clock pulse φ is synchronized with the key scanning timing.
The counter 121, which counts , is reset by the signal SY2 at the start of the second cycle scan. . Therefore, as the key scanning progresses in the second cycle, the count value of the counter 121 increases sequentially. The count output of counter 121 is applied to comparator 118 and compared with the count value stored in latch circuit 111 corresponding to the highest pressed key within the minimum two octave key range. The output EQ of the comparator 118 becomes "1" when the count value of the counter 121 matches the count value of the highest pressed key stored in the latch circuit 111. counter 11
The counting operation at 4 and 121 is the lowest key C2
Since the keys are scanned in synchronization with the key scanning from When scanning is performed in a cycle, the coincidence detection output EQ of the comparator 118 becomes "1". In the example in Figure 7,
A key that is the highest pressed key within a minimum two-octave key range.
Match detection output EQ is “1” at the scanning timing of E3
becomes.

The AND circuit 119 is enabled to operate by the second cycle key scanning interval signal HB, and passes through the coincidence detection output EQ in the second cycle. The coincidence detection output EQ that has passed through the AND circuit 119 is delayed by one bit time in a delay flip-flop 120 and is input to the flip-flop 116 via an OR circuit 117. Therefore, flip-flop 116 is reset after one bit time of match detection output EQ. As a result, the output signal AKRP of the flip-flop 116 falls to "0" at the next scanning timing of the highest pressed key within the minimum two-octave key range.
That is, the signal AKRP becomes "1" only from the start of scanning in the second cycle until the scanning timing of the highest pressed key within the minimum two-octave key range. In the example of FIG. 7, the signal AKRP remains "1" until the scanning timing of the key E3.

The output signal AKRP of flip-flop 116 is
The signal is input to the AND circuit 98 via the switch 115 set to the C mode, and is used as a signal to control the discrimination of the key data KTDM via the OR circuit 96. When the signal AKRP is “1”, the AND circuit 94 is enabled and the key data is
KTDM is distinguished as accompaniment key data AKD. When the signal AKRP becomes “0”, the AND circuit 95
becomes operational, and key data KTDM is distinguished as melody key data MKD. Therefore, when the "C mode" is selected, keys up to the highest pressed key within a minimum two-octave key range are classified into an accompaniment group, and all keys higher than that are classified into a melody group. In the example shown in Fig. 7, the key data KTDM of pressed keys G2, C3, and E3 is distinguished as accompaniment key data AKD, and the pressed keys are distinguished as accompaniment key data AKD.
D4 key data KTDM is key data for melody
Distinguished as MKD. In this C mode, the key ranges that are distinguished into accompaniment groups are not fixed, but move according to the highest pressed key within a minimum two-octave key range.

In addition, if the chord is not established, the signal CHM
Since AKRP is "0", flip-flop 116 is not set and signal AKRP is always "0".
Therefore, only the key data KTDM within the at least one octave key range, which is the accompaniment dedicated key range, becomes the accompaniment key data AKD, and the other key data KTDM becomes the melody key data MKD.

To select "D mode", switch 11
5 to position D opposite to that shown. Thereby, the output of the AND circuit 112 is used as a discrimination control signal. The AND circuit 112 receives the chord formation memory signal CHM and the minimum two octave signal Y24. The output of this AND circuit 112 becomes "1" corresponding to the scanning period of the minimum two-octave key range (keys C2 to B3) on the condition that a chord is established (signal CHM is "1"). Therefore, in the case of "D mode", all key data KTDM in a minimum 2-octave keyboard range (keys C2 to B3) is used as accompaniment key data, provided that the chord is established.
It is distinguished as AKD, and other key ranges (key C4 ~
C6) key data KTDM is distinguished as melody key data MKD. Note that the key range to be discriminated as an accompaniment group is not limited to the key range for which chords are to be detected (minimum two-octave key range), but may also include some nearby key ranges. for that purpose,
Instead of the signal Y24 input to the AND circuit 112, another timing signal corresponding to the desired key range may be input. Also in this D mode, if a chord is not established, the signal CHM input to the AND circuit 112 is "0", so only the key data of the accompaniment-only key area becomes the accompaniment key data AKD.

The melody key data MKD output from the AND circuit 95 is input to the melody tone forming circuit 83, and the accompaniment key data AKD output from the AND circuit 94 is input to the accompaniment tone forming circuit 84. In each musical tone forming circuit 83 and 84, the second
These key data given in the cycle
MKD and AKD are demultiplexed using timing signals HB, SY2, and φ, respectively, and musical tone signals corresponding to the pressed keys indicated by these key data MKD and AKD are generated as melody sounds and accompaniment sounds, respectively. do.

Note that in the above embodiment, the multiplexers 12 and 8
2, scanning is performed in order from the low-pitched keys, but it goes without saying that the present invention can also be applied to a system in which scanning is performed from the high-pitched keys. Furthermore, the key press information generating means is not limited to the multiplexers 12 and 82, but any configuration can be used. For example, the present invention can be applied to an electronic musical instrument that uses a multi-bit key code as key press information, or an electronic musical instrument that uses the output of each key switch in parallel and uses it as key press information.

In addition, in the above embodiment, the key press information is divided into two groups (accompaniment group and melody group), but it is also divided into three groups (for example, melody, accompaniment chord, and accompaniment bass). It is also possible. For example, it is possible to use a key range including chord constituent keys for accompaniment, a range lower than that for bass, and a range higher than that for melody.

In addition, in the example shown in Figure 3, only the chord-constituting keys are classified into the accompaniment group, but all keys in a certain range including the chord-constituting keys (the pressed keys near the chord-constituting keys) are used for accompaniment. It may also be possible to differentiate into different groups. To achieve this, instead of adding the chord constituent note note data CHND** to the AND circuit 69 in the chord constituent note extraction circuit 17, the output of the delay flip-flop 59 may be added.

In addition, in the above embodiment, the keyboards 11 and 81
It has keys C2 to C6 and is intended for a single keyboard. However, the present invention can also be applied to electronic musical instruments equipped with multiple keyboards. For example, if the present invention is applied to a device having an upper keyboard and a lower keyboard, the upper keyboard and the lower keyboard may be treated as one keyboard and chord detection processing and discrimination processing may be performed.

As explained above, according to the present invention, the key press information is classified into different groups depending on whether or not they are composed of chords, and musical tones are formed in different ways for each group. For example, the key range used for performing melody performance and accompaniment performance is no longer limited to a specific key range. In other words, if you press the keys anywhere on the keyboard to form a chord,
The keys pressed in that part will be sounded as accompaniment notes, and virtually the entire keyboard range can be used for accompaniment performance. On the other hand, keys that do not constitute a chord, that is, keys that are pressed as melody sounds, will be sounded as melody sounds no matter where on the keyboard they are pressed, so the entire keyboard range can be used to play the melody. It is also possible to do so. Further, according to the second invention, a pressed key that belongs to a key range over a certain pitch range to which a pressed key that constitutes a chord belongs is in the same group as the chord-forming key even if it is not a chord-forming key. Therefore, even if a special chord that cannot be detected by the chord detection means is pressed, all the constituent keys of such a special chord can be classified into the same group, so that the performance can be performed without any inconvenience. It has the excellent effect of becoming

Further, according to the third invention, a specific limited key range is secured as an accompaniment-only key range, and if there is a pressed key that constitutes a chord in the vicinity of the accompaniment-only key range, the pressed key in the vicinity is By distinguishing keys as accompaniment tones, when keys that do not constitute a chord are pressed as accompaniment tones, by using the accompaniment-only key range, it becomes possible to distinguish them as accompaniment tones. This has an excellent effect in that the key range to be used can be flexibly extended to neighboring key ranges without being limited to the accompaniment-only key range when performing a key performance.

[Brief explanation of the drawing]

1 is a block diagram showing the overall configuration of an embodiment of the present invention, FIG. 2 is a timing chart showing the relationship between various timing signals used in FIGS. 1 and 3, and FIG. 3 is a timing chart showing the relationship between various timing signals used in FIGS. FIG. 4 is a circuit diagram showing a detailed example of the chord detection means and discriminating means; FIG. 4 is a timing chart showing an example of the operation of the circuit shown in FIG. FIG. 6 is a block diagram showing another embodiment of the present invention, and FIG. 7 is a timing chart showing an example of the operation of the circuit shown in FIG. 11, 81... Keyboard, 12, 82... Multiplexer (key press information generation means), 13, 89... Chord detection means, 14, 90... Discrimination means, 15...
Predetermined number of pressed keys existing key area detection circuit, 16, 105...
...Chord formation detection circuit, 17...Chord constituent sound extraction circuit, 75, 83...Melody musical tone formation circuit, 7
6, 84...accompaniment tone forming circuit, 99...key range control circuit, KTDM, KTDM*, KTDM**...
Time division multiplexed key data (key press information), AKD...
Accompaniment key data, MKD...melody key data.

Claims (1)

[Scope of Claims] 1. A keyboard, a pressed key information generating means for generating pressed key information corresponding to pressed keys on the keyboard, and a plurality of pressed keys constituting a chord from among the pressed keys on the keyboard. a chord detecting means for detecting a chord; and based on the detection by the chord detecting means, among the key press information generated from the key press information generating means, key press information corresponding to the pressed keys forming the chord and other key press information a discriminating means for discriminating pressed key information corresponding to pressed keys into different groups; and forming a musical tone signal corresponding to the pressed key information discriminated into each group by the discriminating means in a different manner for each group. An electronic musical instrument comprising a musical tone forming means and. 2. The chord detection means includes a key range detection circuit that detects a key range in which there are a predetermined number or more of pressed keys sufficient to form a chord within a certain pitch range; A chord formation detection circuit detects whether or not a chord is formed by the pressed keys in the key range, and a chord formation detection circuit that detects whether a chord is formed by the pressed keys in the key range, and a chord formation detection circuit that detects the chord constituent notes from among the pressed keys in the key range according to the type of chord whose formation is detected. 2. The electronic musical instrument according to claim 1, further comprising a chord constituent tone extracting circuit for selecting a plurality of keys to be pressed. 3. A keyboard, a pressed key information generating means for generating pressed key information corresponding to pressed keys on the keyboard, and a chord detecting means for detecting a plurality of pressed keys constituting a chord from among the pressed keys on the keyboard. and a key range indicating means for indicating a key range over a certain pitch range to which the pressed keys constituting the chord belong based on the detection by the chord detecting means, and the pressed keys generated by the pressed key information generating means. discriminating means for discriminating, among the information, key press information corresponding to pressed keys belonging to the key range designated by the key range indicating means and pressed key information corresponding to other pressed keys into separate groups; An electronic musical instrument comprising: musical tone forming means for forming musical tone signals corresponding to the key press information discriminated into each group by the discriminating means in a different manner for each group. 4. A keyboard comprising a first key range, a second key range adjacent to the first key range, and a remaining key range; key press information generating means for generating key press information corresponding to pressed keys on the keyboard; Based on the pressed key information generated from the key information generating means, it is detected whether a chord is formed by a plurality of pressed keys belonging to at least one of the first key range and the second key range. a chord detecting means; and a chord detecting means, which always discriminates key press information of pressed keys belonging to the first key range into a first group, and detecting the second key on the condition that formation of a chord is detected by the chord detecting means. a discrimination means for discriminating key press information of pressed keys in the area into a first group and discriminating key press information of other pressed keys into a second group; An electronic musical instrument comprising: musical tone forming means for forming musical tone signals corresponding to key information in a different manner for each group. 5. The chord detecting means detects whether or not a chord is formed on the condition that at least one of the pressed keys constituting the chord belongs to the first key range. The electronic musical instrument according to item 4.