JPH0764561A - Electronic musical instrument - Google Patents

Abstract

PURPOSE:To exactly detect a chord based on performance data generated in a normal performing state without operating any special performance for detecting the chord. CONSTITUTION:An inputting means inputs performance data corresponding to a performance. When data related with keyboard depression and detachment are present in the performance data, the data related with the keyboard depression or the data related with the keyboard detachment are inputted from the inputting means, and the state is always changed. Then, a chord detecting means detects the chord in each rhythm timing corresponding to the prescribed musical note length of automatic accompaniment which is not related with the inputting time of the performance data from the inputting means, and detects the chord in each timing near the rhythm timing and separated from the rhythm timing only in a prescribed time. Thus, when the rhythm timing is not matched with the timing of the performance, that is, even when the performance data are inputted with a little delay from the rhythm timing, the chord can be exactly detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic musical instrument having a chord detecting function for detecting chords based on performance data generated in response to performance of a keyboard instrument or the like.

[0002]

2. Description of the Related Art A chord detection device built into an electronic musical instrument is
For example, it detects the root note and type of chord corresponding to the performance data generated by playing the keyboard (key pressing), that is, the combination of the on / off states of each note (key pressing pattern). is there. The conventional chord detection device detects a chord each time a key press event occurs based on the key press pattern, or a predetermined time elapses after the first key press event occurs in the state where all keys are released. The chord was detected according to the pattern of the key depression event that occurred until the time.

[0003]

However, in the conventional method, the chord cannot be detected unless all the keys are released before the new chord is detected. A special performance for chord detection must be performed so that the keys are released. Under normal performance conditions (melody performance, etc.), chords cannot be detected unless all keys are released. Have the problem.

The present invention has been made in view of the above points, and can accurately detect chords on the basis of performance data generated in a normal performance state without performing a special performance for detecting chords. It is an object of the present invention to provide an electronic musical instrument having a chord detection function capable of performing.

[0005]

An electronic musical instrument according to the present invention comprises an input means for inputting performance data corresponding to a performance,
Chord detection means for detecting chords based on the performance data at each beat timing according to a predetermined note length of the automatic accompaniment, and at each timing near the beat timing and separated from the beat timing by a predetermined time. It is equipped with.

[0006]

In the past, when performance data regarding key depression was input, chord detection processing was performed in synchronization with the input time. However, the electronic musical instrument of the present invention has a beat timing according to a predetermined note length of the automatic accompaniment irrespective of the input time of performance data, and a timing near the beat timing, which is a timing separated from the beat timing by a predetermined time. In addition, chords are detected. In other words, among the performance data, there are data related to key depression and key release, so that the state of the key change and the data release related to the key input are constantly changing. ing. However, since chords are usually played at each beat timing, key depression and key release occur concentrated on the beat timing. Therefore, the chord detecting means detects the chord at each beat timing that is unrelated to the input time of the performance data from the input means. Therefore, the chord can be accurately detected by detecting the chord for each beat timing based on the performance data at that time. However, in the actual performance, the beat timing and the performance timing do not completely match,
Performance data may be input slightly later than the beat timing. Therefore, in the present invention, the chord is detected at each beat timing, and the chord is also detected at each timing near the beat timing and separated from the beat timing by a predetermined time. by this,
It becomes possible to detect the chord more accurately.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 2 is a block diagram showing the hardware configuration of an electronic musical instrument incorporating the chord detection device according to the present invention. The electronic musical instrument of this embodiment includes a microprocessor unit (CPU) 21, a program memory (RO).
M) 22 and working memory (RAM) 23, and various processes are executed under the control of a microcomputer.

The CPU 21 controls the operation of the electronic musical instrument as a whole. To the CPU 21, a program memory 22, a data and address bus 2C,
A working memory 23, an automatic accompaniment device 24, a key depression detection circuit 25, a switch detection circuit 26, and a tone generator circuit 27 are connected.

The program memory 22 stores the system program of the CPU 21, various parameters relating to musical sounds, various data, etc., and is composed of a read only memory (ROM). Working memory 23
Is a memory for temporarily storing various data and flags generated when the CPU 21 executes a program, and a predetermined address area of a random access memory (RAM) is allocated to each. The automatic accompaniment device 24 has a built-in accompaniment pattern memory that stores data regarding roots and types of chords, data regarding bass progression, etc., and sequentially reads out these data according to the tempo clock from the timer 2B. To generate an automatic accompaniment sound.

The keyboard 28 is provided with a plurality of keys for selecting the pitch of a musical tone to be generated, has a key switch corresponding to each key, and if necessary, a pressing force detecting device or the like. It has a touch detection means. The keyboard 28 is a basic operator for playing music, and it goes without saying that other keyboard operators may be used.

The key depression detection circuit 25 includes a key switch circuit provided corresponding to each key of the keyboard 28 for designating the pitch of a musical tone to be generated. The key press detecting circuit 25 detects a change of the keyboard 28 from a key release state to a key press state and outputs a key-on event, and detects a change from the key press state to a key release state and outputs a key off event. A key code (note number) indicating the pitch of the key for each key-on event and key-off event
Is output. In addition to this, the key-depression detection circuit 25 detects the key-depression operation speed, the pressure, and the like when the key is depressed and outputs it as velocity data or after-touch data.

The switch detection circuit 26 is provided in correspondence with each operator (switch) provided on the panel switch 29, and outputs operation data corresponding to the operation status of each operator as event information. . The panel switch 29 includes various operators for selecting, setting, and controlling automatic accompaniment start / stop, accompaniment style, tone color of tone to be generated, volume, pitch, effect and the like.

The tone generator circuit 27 is capable of simultaneously generating musical tone signals on a plurality of channels, inputs data and performance data given via the address bus 2C, and produces musical tones such as melody sounds and accompaniment tones based on the input data. Generate a signal.
Any tone signal generation method may be used in the tone generator circuit 27. For example, a memory reading method for sequentially reading the musical tone waveform sample value data stored in the waveform memory according to the address data that changes corresponding to the pitch of the musical tone to be generated, or a predetermined frequency with the address data as phase angle parameter data. A well-known method such as an FM method for performing a modulation operation to obtain musical tone waveform sample value data or an AM method for performing a predetermined amplitude modulation operation using the address data as phase angle parameter data to obtain a tone waveform sample value data. You may employ suitably.

The tone signal output from the tone generator circuit 27 is a digital-analog converter (A) in the sound system 2A.
DC), an amplifier and a speaker. The timer 2B generates a tempo clock pulse for measuring a predetermined time interval for chord detection and setting the tempo of automatic accompaniment. The frequency of this tempo clock pulse is the tempo switch on the panel switch 29. (Not shown). The generated tempo clock is given to the CPU 21 and the automatic accompaniment device 24 as a timer interrupt command, and the automatic accompaniment device 24 executes various automatic accompaniment processes by timer interrupt processing.

Next, an example of the processing of the chord detection device executed by the microcomputer will be described with reference to FIGS.
Description will be made based on the flowcharts of FIGS. 5, 7, 8 and 9. FIG. 3 is a diagram showing an example of a main routine processed by the microcomputer. This main routine is sequentially executed in the following steps.

Step 31: First, when the power is turned on, the CPU 21 starts the processing according to the control program stored in the program memory 22. Then, in this "initial setting" processing, various registers and flags in the working memory 23 are initialized. Step 32: The keyboard 2 is scanned to scan the keyboard 2
8 is operated and it is determined whether or not a key event has occurred. If there is a key event (YES), the key event process of the next step 33 is executed, then the process proceeds to step 34, and there is no key event (NO). If step 34
Proceed to.

Step 33 is a key event process which is performed every time the keyboard 28 is operated and a key event occurs. Details of this key event processing are shown in FIG. Step 34: The switch detection circuit 26 is scanned to determine whether the start / stop switch is operated to generate an on event, and an on event is present (Y
If it is ES), the process proceeds to step 35, and if there is no on-event (NO), the process proceeds to step 3A.

Step 35: Performance running state flag RUN
Invert. That is, in this embodiment, the automatic accompaniment starts or stops each time the start / stop switch is operated. Step 36: It is determined whether or not the performance running state flag RUN is "1". If "1" (YES), that is, if automatic accompaniment is started, the process proceeds to step 37. If not (NO), that is, automatic If the accompaniment is stopped, the process proceeds to step 39.

Step 37: As a result of the performance running state flag RUN being inverted in the process of the previous step 36, it is determined that it is "1", that is, the automatic accompaniment is started. A start signal is output to 24. Step 38: Reset the tempo clock register CLK to "0" in response to a new start of automatic accompaniment. Step 39: Similarly, as a result of the performance running state flag RUN being inverted in the process of the previous step 36, it is determined that it is "0", that is, the automatic accompaniment is stopped, and therefore the stop signal is sent to the automatic accompaniment device 24. Is output. Step 3A: Various processes such as a process based on the operation of another operator on the panel switch 29 and other volume changing process are performed.

FIG. 4 is a diagram showing an example of the key event processing of step 33 of FIG. 3 processed by the microcomputer. In this key event processing, the keyboard 28 is operated,
Each time a key event occurs, the following steps are executed in sequence.

Step 41: It is judged whether or not the key event is the key-on event, and the key-on event (YES)
If No, the process proceeds to Step 42. If not (NO), the process proceeds to Step 43. Step 42: Since the key-on event is determined in the previous step 41, the tone generation process (key-on process) of the key code corresponding to the key-on event is performed. Step 43: Store all the key codes currently being depressed in the key code list register KCLST.

Step 44: Since the key-off event is determined in the previous step 41, the mute processing (key-off processing) of the key code corresponding to the key-off event is performed. Step 45: Set the value of tempo clock register CLK to 1
It is determined whether the remainder (CLKmod12) divided by 2 is “0”. If “0” (YES), the process returns to the main routine of FIG. 3, and if it is a value other than “0” (NO), the step is performed. Proceed to 43. In this embodiment, one measure is 96 minutes long, and quarter notes are 2 minutes long.
A quarter note and an eighth note are 12 minutes long. Since the tempo clock register CLK repeatedly accumulates the values of "0" to "95", if the remainder (CLKmod12) obtained by dividing this value by the eighth note length "12" is "0", It means that the timing is exactly the eighth note, that is, the beat timing.

That is, in this key event processing, when a key-on event occurs, the key code corresponding to the key-on event is stored in the key code list register K.
The key code corresponding to the key-off event is stored in CLST and the key code corresponding to the key-off event is deleted from the key code list register KCLST. However, the value of the tempo clock register CLK is divided by 12 For a key-off event that occurs between (CLKmod12) becomes "0" and "1", the key code corresponding to the key-off event is returned without being deleted from the key code list register KCLST. ing. This allows CLK
All the key codes that have been in the key-depressed state from the time when the mod12 becomes "0" to the time when it becomes "1" are stored in the key code list register KCLST.

FIG. 5 is a diagram showing a timer interrupt process executed by 96 interrupts per bar. Figure 6
FIG. 6 is a diagram for explaining operations of chord detection processing and legato processing executed by the timer interrupt processing of FIG. 5.
In FIG. 6, the horizontal axis represents time and the vertical axis represents the key depression state at that time. The timer interrupt process of FIG. 5 is executed by interrupting 96 times per bar. Corresponding to this, the lower part of FIG. 6 shows the values (23 to 39) of the tempo clock register CLK in order to show the current interrupt timing.

Further, in this timer interrupt processing, the key-depression state is detected one minute before and after the timing of the eighth note as a reference, and the chord is detected accordingly. Correspondingly, in the upper part of FIG. 6, the remainder of the value of the tempo clock register CLK divided by 12 (CLKmod
12) is a pre-timing PRE that indicates the case of "11",
Just timing JUST indicating the case of "0",
The late timing LATE showing the case of "1" is shown respectively. In FIG. 6, the key with the key code K1 is pressed between the interrupt timings 24 and 25 and released between the interrupt timings 39 and 40. The key with the key code K2 is pressed between the interrupt timings 23 and 24 and released between the interrupt timings 39 and 40.
The key with the key code K3 is pressed between the interrupt timings 35 and 36, and released from between the interrupt timings 39 and 40. The key of key code K4 is interrupt timing 2
The key is pressed between 3 and 24, and the key is released between interrupt timings 36 and 37. The key with the key code K5 is pressed at the interrupt timing 28 and released at the interrupt timing 34.

The timer interrupt process of FIG. 5 is sequentially executed in the following steps. Step 51: It is determined whether or not the performance running state flag RUN is "1". If "1" (YES), that is, if automatic accompaniment is started, the process proceeds to step 52. If not (NO), that is, automatic If the accompaniment is stopped, the process proceeds to step 54. Step 52: Set the value of tempo clock register CLK to 1
Is the remainder (CLKmod12) divided by 2 "11"?
It is judged whether it is "0" or "1", and "1"
If it is "1", "0" or "1" (YES), the process proceeds to the next step 53, and if it is any other value (NO), the process proceeds to step 54. Step 53: Set the value of tempo clock register CLK to 1
The remainder (CLKmod12) divided by 2 is "11",
In the case of "0" and "1", that is, the pre-timing PRE (interrupt timing 23 and 35), the just timing JUST (interrupt timing 24 and 36) and the late timing LATE (interrupt timing 25 and 3) of FIG.
The key-depression state detection processing for detecting the key-depression state in each of 7) is performed. Details of this key-depression state detection processing will be described later. Step 54: Increment the value of the tempo clock register CLK by "1" and return. As a result, the interrupt timing is increased by one.

FIG. 1 is a diagram showing details of the key-depression state detection processing in step 53 of FIG. In the key-depression state detection processing, as described above, the remainder (CLKmod12) obtained by dividing the value of the tempo clock register CLK by 12 is "11".
(Pre-tamming PRE), "0" (just timing JUST) or "1" (late timing LATE)
In case of. This key-depression state detection processing is sequentially executed in the following steps. Step 11: The key code in the current list register CLST is stored in the prelist register PLST. Step 12: The key code in the key code list register KCLST is stored in the current list register CLST.

Through the processing of steps 11 and 12, the prelist register PLST stores the key code at the interrupt timing one time before, and the current list register CLST stores all the key codes currently being depressed. . By the determination processing of step 45 of FIG. 4, for the key-off event that occurs between the time when the remainder (CLKmod12) obtained by dividing the value of the tempo clock register CLK by 12 becomes “1”, Since the key code corresponding to the key-off event is returned without being deleted from the key code list register KCLST, even if a key-off event occurs between the just timing JUST and the late timing LATE, it is ignored. , Key code list register KCLST
It is additionally stored in. For example, in FIG. 6, the key code K4
This corresponds to the key state in which the key No. is released between the interrupt timings 36 and 37, and the key with the key code K3 is pressed between the interrupt timings 35 and 36.

Step 13: It is judged whether the continuation flag CF is "1", and if "1" (YES), the step 1
7. If "0" (NO), proceed to step 14. The continuation flag CF is set to "1" in step 16 when both of the processes of steps 14 and 15 are determined to be YES, and is set to "0" when NO of the process in step 17 is determined. . For example, in FIG. 6, the determination in step 13 is YES at the interrupt timing 36, and other interrupt timings 23, 24, 25, 35.
And 37 are NO.

Step 14: Since it was determined in the previous step 13 that key depression is not continuing, in this step, the remainder of the value of the tempo clock register CLK divided by 12 (CL
It is determined whether Kmod12) is "11" (pre-timing PRE). If "11" (YES), the process proceeds to step 15. If not (NO), step 1C is performed.
Proceed to. For example, in FIG. 6, the determination in step 14 is YES at interrupt timings 23 and 35, and NO at other interrupt timings 24, 25, and 37.

Step 15: It is determined in the previous step 14 that the current interrupt timing is the pre-timing PRE, which means that the key code at the previous late timing LATE is stored in the pre-list register PLST in step 11. Since the key code at the current pre-timing PRE is stored in the current list register CLST in step 12, it is determined in step 15 whether all the key codes in the current list register CLST belong to the key codes in the pre-list register PLST. If it belongs (YES), that is, if there is continuity in key depression, proceed to the next step 16,
If it does not belong (NO), that is, if there is no continuity in key depression, the process proceeds to step 1C.

That is, the current list register CLS
All the key codes in T belong to the key code in the pre-list register PLST, which means that the key press at the previous late timing LATE is the pre-timing P at this time.
This means that the RE continues, and the fact that it does not belong to the contrary means that a new key release or key depression is performed. For example, in FIG. 6, the key codes of the interrupt timing 25 (late timing LATE) are K1, K2 and K4.
And the interrupt timing 35 (pre-timing PRE)
Since the key codes of K are K1, K2, and K4, it is determined in this case that the key depression is continuous. Therefore, in FIG. 6, the determination at step 15 is YES at the interrupt timing 35.
And becomes NO at other interrupt timings 23.

Step 16: The current interrupt timing is the pre-timing PRE in the previous Step 14, and it is determined in Step 15 that all the key codes in the current list register CLST belong to the key codes in the prelist register PLST. This means that the key press at the previous late timing LATE and the pre-timing P at this time
This means that there is continuity with the key depression in RE, so in this step, the continuation flag CF is set to "1".
And set to step 1C. Therefore, in FIG. 6, "1" is set to the continuation flag CF at the interrupt timing 35.

Step 17: Since it is determined in the previous step 13 that the continuation flag CF is "1", that is, key depression is in progress, the current list register C is determined in this step.
All key codes in LST are prelist register PLS
Whether or not it belongs to the key code in T is judged, and if it belongs (YES), the process proceeds to step 18 and does not belong (N
If O), proceed to step 19. That is, since it is determined in the previous step 13 that key depression is continuing, it is determined whether key depression is still continuing between the previous key depression state detection process and the current key depression state detection process. There is.

All the key codes in the current list register CLST belong to the key codes in the pre-list register PLST (YES), which means that the key press at the previous pre-timing PRE is the just timing J at this time.
It means that it continues in UST, or that the key press at the last just timing JUST continues at this late timing LATE, or the key is released during that time, and it does not belong to the contrary (NO). Is the previous pre-timing PRE and this just timing J
If there is a new key press with UST, or just before last timing JUST and this late timing L
This means a case where a new key is pressed with the ATE. For example, in FIG. 6, step 1 at the interrupt timing 36
The determination of 7 does not belong (NO).

Step 18: Since it is determined in step 13 that key depression is in progress, and in step 17 that key depression is in progress this time as well, in this step the remainder of the value of the tempo clock register CLK divided by 12 ( CLKmod1
It is determined whether 2) is “0”, that is, whether the interrupt timing is just timing JUST, and “0” is determined.
If (YES), the current interrupt timing is the just timing JUST, so the process proceeds to step 1C to perform part division processing. If not (NO), the current interrupt timing is the pre-timing PRE or late timing LATE, so the step Go to 1D.

Step 19: Since it is determined in step 17 that all the key codes in the current list register CLST do not belong to the key codes in the prelist register PLST (NO), a new code is added between the previous timing and the current timing. Since this means that there is a key depression, the continuation flag CF is reset to "0" in this step. Therefore, in FIG. 6, the continuation flag CF is reset to "0" by the interrupt timing 36.

Step 1A: Tempo clock register C
It is determined whether the remainder (CLKmod12) obtained by dividing the value of LK by 12 is "11", that is, whether the interrupt timing is the pre-timing PRE, and "11" (YES).
In the case of, proceed to step 1C, and "0" or "1" (N
In the case of O), proceed to the next step 1B.

For example, in FIG. 6, the determination at step 1A at the interrupt timing 36 is NO (just timing).

Step 1B: It is determined that the key depression is continuing and there is a new key depression, and the interrupt timing is the just timing JUST or the late timing L.
Since it corresponds to the case of ATE, legato processing is performed. The details of this legato processing are shown in FIG. Step 1C: Part division processing for dividing the key code in the current list register CLST into predetermined parts is performed. Details of this part division processing will be described later with reference to FIG. 7.

Step 1D: Tempo clock register C
It is determined whether the remainder (CLKmod12) obtained by dividing the value of LK by 12 is "11". If "11" (YES), chord detection processing is not necessary, so proceed to step 1F, otherwise (NO). ), The process proceeds to the next step 1E for performing the chord detection process. Step 1E: Perform chord detection processing based on the key code divided into each part in the previous step 1C. Details of the chord detection process will be described later with reference to FIG. Step 1F: Since the contents of the current list register CLST may have been changed by the legato processing of the previous step 1B, the key code in the key code list register KCLST is stored again in the current list register CLST as in step 12. .

FIG. 7 is a diagram showing details of the part division processing in step 1C of FIG. In this part division processing, the key code stored in the current list register CLST is divided into each part (melody part, bass part, chord part). This part division processing is sequentially executed in the following steps.

Step 71: Current list register C
It is determined whether or not the number of components (key code) of LST is two tones or less, and if two tones or less (YES), step 72
If three or more tones (NO), go to step 73. Step 72: Since it is determined in the previous step 71 that the number of constituent elements (key code) of the current list register CLST is two or less, the current list register CLST
According to the tone range to which the key chord belongs (for example, the treble range when the keyboard is divided into three is the melody part, the middle tone range is the chord part, and the bass range is the bass part) (melody part, bass part, Chord part) and assign it to each melody part register M, bass part register B and chord part register C with two notes or one.
Store the sound.

Step 73: Current list register C
It is determined whether or not the number of LST components (key code) is three tones, and if three tones (YES), the process proceeds to step 74.
If four or more sounds (NO), the process proceeds to step 75. Step 74: Since it is determined in the previous step 73 that the number of constituent elements (key chords) of the current list register CLST is three tones, it is assumed that the key chord in the current list register CLST corresponds to the chord part. An empty set φ is stored in each of M and the base part register B, and three constituent elements (key codes) in the current list register CLST are stored in the code part register C.

Step 75: Current list register C
It is determined whether the number of LST components (key code) is four tones, and if four tones (YES), the process proceeds to step 76.
If there are five or more tones (NO), the process proceeds to step 79. Step 76: Since it is determined in the previous step 75 that the number of constituent elements (key code) of the current list register CLST is four tones, the key code of the highest tone in the current list register CLST is a tone of key code number C4 or more. It is determined whether the pitch is high or not. If the pitch is C4 or higher (YES), the process proceeds to step 77, and if the pitch is lower than C4, the process proceeds to step 78.

Step 77: Since the key code of the highest note in the current list register CLST is judged to be the pitch higher than the key code number C4 in the previous step 76, the highest note (one note) of this note is selected in this step. The key code is stored in the melody part register M, the remaining three tones are stored in the chord part register C, and the empty set φ is stored in the bass part register B. Step 78: Since it was determined in the previous step 76 that the key code of the highest note in the current list register CLST has a pitch lower than the key code number C4, in this step, the key code of the lowest note (one note). Is stored in the bass part register B, the remaining three notes are stored in the chord part register C, and the empty set φ is stored in the melody part register M.
To store.

Step 79: Since it is determined in the previous step 75 that the number of constituent elements (key code) of the current list register CLST is five or more tones, the key of the highest tone (one note) in the current list register CLST is determined. The chord is stored in the melody part register M, and the lowest note (1 note)
The key code is stored in the bass part register B, and the three tones or all the remaining tones other than the highest and lowest tones are stored in the chord part register C.

FIG. 8 is a diagram showing details of the chord detection process in step 1E of FIG. The chord detection process is performed according to the key code in the chord part register C and the bass part register B divided by the part division process of FIG. This chord detection process is sequentially executed in the following steps. Step 81: Determine whether the set of code part registers C is an empty set φ. If it is an empty set φ (YES), proceed to step 8B. If it is not an empty set φ (NO), proceed to step 82. Step 82: It is judged whether or not the set of the base part register B is the empty set φ. If it is the empty set φ (YES), the process proceeds to step 87. If it is not the empty set φ (NO), the process proceeds to step 83.

Step 83: Previous Steps 81 and 83
Since it is determined that both the code part register C and the base part register B are not the empty set φ, the key codes in the code part register C and the base part register B are stored in the code base register CB in this step. Step 84: Detect a chord based on the component (key code) stored in the chord base register CB.

Step 85: It is judged whether or not the chord can be detected in the previous step 84. If it can be detected (YES), the procedure proceeds to step 86, and if it cannot be detected (NO), the procedure proceeds to step 87. . Step 86: The hexadecimal number "F" (indicated by FH in the figure) meaning the empty set φ is stored in the base register BS. Step 87: When the key code is stored in the code part register C but it is determined in step 82 that the base part register B is empty, or step 85
Since it is determined that the chord is not detected based on the component (key code) in the chord base register CB, the chord is detected based on the component (key code) in the chord part register C.

Step 88: It is judged whether or not the chord can be detected in the previous step 87, and if it can be detected (YES), the procedure proceeds to step 89, and if it cannot be detected (NO), the step of FIG. Return to 1F. Step 89: Since a chord has been detected in the previous step 87, in this step, the remainder obtained by dividing the component (key code) of the bass part register B by 12 is stored in the bass register BS, that is, the note name. When the base part register B is empty, a hexadecimal number "F" (indicated by FH in the figure) meaning an empty set φ is stored.

Step 8A: The root note of the detected chord is stored in the root note register RT, and the detected chord type is stored in the chord type register TP. Step 8B: The root note, chord type, and bass note stored in the root note register RT, the chord type register TP, and the bass register BS are output to the automatic accompaniment device 24. As a result, the automatic accompaniment device 24 performs accompaniment based on the detected chord. The base register BS
When the stored value of is "FH", the bass sound corresponding to the detected chord is generated and accompanied by the automatic accompaniment device 24 side.

FIG. 9 is a diagram showing the detailed structure of the legato processing in step 1B of FIG. This legato processing is performed according to the key code divided and stored in the chord part register C and the melody part register M in the part division processing of FIG. For example, in FIG. 6, this legato processing is performed at the interrupt timing 36. This legato processing is sequentially executed in the following steps. Step 91: The key codes of the chord part register C and the melody part register M are stored in the chord melody register CM. Step 92: The lowest pitched note (bottom note) of the key chords stored in the chord melody register CM is stored in the chord bottom register CBot, and the highest pitched note (top note) is chorded top. Store in register CTtop.

Step 93: It is judged whether the code part register C is an empty set φ. If it is an empty set φ (YES), the process proceeds to step 94. If it is not the empty set φ (NO), the process proceeds to step 96. Step 94: In the current list register CLST, a tone string (key chord string) having a pitch equal to or higher than the key code of the chord bottom register CBot is stored in the current overlap chord register COCBot. Step 95: Current overlap code register C
It is determined whether the key code stored in OCBot is equal to the sum of the key code stored in the chord melody register CM and the sound (key code) within 6 degrees above and below the chord top register CTop. However, if they are equal (YES), that is, if the key depression state is the legato state, the routine proceeds to step 99. If they are not equal (NO), that is, if the key depression state is not the legato state, the routine returns to step 1C of FIG. To do.

Step 96: Since it was determined in the previous step 93 that the chord part register C is the empty set φ, it is determined in this step whether the melody part register M is the empty set φ, and the empty set φ (YES). In the case of, it means that there is no key depression corresponding to the melody part and the chord part. Therefore, the process returns to step 1C of FIG. Is present, the process proceeds to step 96. Step 97: In the current list register CLST, a tone sequence (key code sequence) within 6 degrees above and below the key code of the melody part register M is stored in the current overlap melody register COM. Step 98: The key code stored in the current overlap melody register COM adds the key code stored in the chord melody register CM and the sound (key code) within 6 degrees above and below the melody part register M. If it is equal (YES), that is, if the key depression state is the legato state, the process proceeds to step 99 and is not equal (NO).
In the case, that is, when the key depression state is not the legato state, the process returns to step 1C of FIG.

Although the electronic musical instrument has been described in the above embodiments, a sequencer module for performing automatic accompaniment processing and a tone generator module including a key-depression detection circuit and a tone generator circuit are separately configured, and data is exchanged between the modules. It is needless to say that the same can be applied to a device configured to comply with the well-known MIDI standard. Further, in the above-described embodiment, the case where the key code is not deleted from the key code list register KCLST even if a key-off event occurs between the just timing JUST and the late timing LATE has been described. Timing LAT
Similar processing may be performed even when a key-off event occurs up to E. Further, in the above-described embodiment, the case where the part division process of FIG. 7 and the chord detection process of FIG. 8 are performed at the same timing has been described, but only the part division process is performed finer than the timing of the chord detection process. Good. That is, the chord detection process may be performed at the timing of the eighth note length, and the part division process may be performed at the timing of the 32nd note length.

[0057]

According to the present invention, there is an effect that a chord can be accurately detected based on performance data generated in a normal performance state without performing a special performance for detecting the chord.

[Brief description of drawings]

FIG. 1 is a diagram showing details of key-depression state detection processing in the timer interrupt processing of FIG.

FIG. 2 is a block diagram showing a hardware configuration of an electronic musical instrument having a chord detection function according to the present invention.

FIG. 3 is a diagram showing an example of a main routine processed by a microcomputer.

FIG. 4 is a diagram showing an example of the key event process of FIG. 3, which is processed by the microcomputer every time the keyboard is operated.

FIG. 5 is a diagram showing details of timer interrupt processing executed by interrupting 96 times per bar.

FIG. 6 is a diagram for explaining operations of chord detection processing and legato processing executed by the timer interrupt processing of FIG.

7 is a diagram showing details of part division processing in the timer interrupt processing of FIG.

FIG. 8 is a diagram showing details of chord detection processing in the timer interrupt processing of FIG.

9 is a diagram showing details of legato processing in the timer interrupt processing of FIG.

[Explanation of symbols]

21 ... CPU, 22 ... Program memory, 23 ... Working memory, 24 ... Automatic accompaniment device, 25 ... Key detection circuit, 26 ... Switch detection circuit, 27 tone generator circuit, 28 ... Keyboard, 29 ... Panel switch, 2A ... Sound system ,
2B ... timer, 2C ... data and address bus

Claims (1)

[Claims] 1. Input means for inputting performance data corresponding to a performance, each beat timing according to a predetermined note length of an automatic accompaniment, and a timing near the beat timing and separated from the beat timing by a predetermined time. An electronic musical instrument characterized by comprising chord detection means for detecting a chord based on the performance data.