JPH0728467A - Chord detecting device - Google Patents

Abstract

PURPOSE:To accurately detect a chord on the basis of musical performance data which are generated in a normal musical performance state without any special musical performance for chord detection. CONSTITUTION:An input means input musical performance data regarding key depression, key release, etc., which are generated according to operation on a keyboard 8, etc. A key depression state detecting means 5 detects a key depression state within a specific time on the basis of the musical performance data inputted through this input means. A chord detecting means detects a chord with a specific reference time signal irrelevantly to the input time of the musical performance data from the input means on the basis of the key depression state detected by the key depression state detecting means 5 at specific periodically set intervals of time and the musical performance data corresponding to the key depression state. For example, when there is only one peak of the number of depressed keys in a specific time, the chord is detected on the basis of the musical performance data at the peak time and when there are >=2 peaks of the number of depressed keys, the chord is detected on the basis of the musical performance data at peak time right before it or on the basis of the musical performance data generated when the longest peak time is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chord detecting device 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 detecting device generates chords corresponding to a combination of performance data, that is, a combination of on / off states of each note (key depression pattern), which is generated by playing a keyboard of an electronic musical instrument (key depression). Root sound and type
Is to detect. 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 a chord detection device capable of playing.

[0005]

SUMMARY OF THE INVENTION A chord detecting device according to the present invention detects a key-depression state within a predetermined time on the basis of input means for inputting performance data generated corresponding to a performance and the performance data. The key-depression state detecting means and the key-depression state detecting means detect the key-depression state at every predetermined time which is periodically set based on a predetermined reference time signal irrespective of the input time of the performance data from the input means. It is provided with chord detection means for detecting a chord based on a key-depressed state and performance data corresponding to the key-depressed state.

[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 chord detection device of the present invention detects chords at predetermined time intervals that are periodically set based on a predetermined reference time signal, regardless of the input time of performance data. That is, the key-depression state detecting means detects the key-depression state within the predetermined time, based on the performance data successively input from the input means. That is, since the performance data includes data related to key depression and key release, the key depression state detection means increases by 1 when data related to key depression is input from the input means within a predetermined time, and the key release state is released. When the data related to the key is input, it is decreased by 1
A change in the number of key presses within a predetermined time is detected as a key press state.

The chord detecting means is based on the key-depression state and the performance data detected by the key-depression state detecting means, and periodically based on a predetermined reference time signal regardless of the input time of the performance data from the input means. The chord is detected at every predetermined time set to. That is, the key depression state changes variously within a predetermined time period according to the data regarding key depression and key release, so that the chord detection means can detect the chord most efficiently based on the key depression state within the predetermined time period. Detect chords in any way you can. For example, when there is only one peak in the number of key presses within a predetermined time, a chord is detected based on the performance data at the peak, or when there are two or more peak key presses. , A chord is detected based on the performance data at the immediately preceding peak time, or a chord is detected based on the performance data at the longest peak time. This makes it possible to accurately detect chords on the basis of performance data generated in a normal performance state without performing a special performance for detecting chords.

[0008]

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) 1, a program memory (RO
M) 2 and various memories are executed under the control of a microcomputer including a working memory (RAM) 3.

The CPU 1 controls the operation of the entire electronic musical instrument. A program memory 2, a working memory 3, an automatic accompaniment device 4, a key pressing detection circuit 5, a switch detection circuit 6, and a tone generator circuit 7 are connected to the CPU 1 via a data and address bus 13.

The program memory 2 stores a system program of the CPU 1, various parameters and various data relating to musical tones, and is composed of a read only memory (ROM). Working memory 3
The CPU 1 temporarily stores various data and flags generated when the CPU 1 executes the program, and a predetermined address area of a random access memory (RAM) is allocated to each. The automatic accompaniment apparatus 4 has a built-in accompaniment pattern memory that stores data regarding roots and types of chords, data regarding bass progression, and the like, and generates automatic accompaniment sounds based on these data.

The keyboard 8 is provided with a plurality of keys for selecting the pitch of a musical tone to be produced, 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. It is needless to say that the keyboard 8 is a basic operator for playing music, and may be a performance operator other than this.

The key depression detection circuit 5 includes a key switch circuit provided corresponding to each key of the keyboard 8 for designating the pitch of a musical tone to be generated. The key-depression detection circuit 5 detects a change from the key-released state to a key-depressed state of the keyboard 8 and outputs a key-on event, and detects a change from the key-depressed state to the key-released state and outputs a key-off event. At the same time, 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 5 detects a key-depression operation speed, a pressure, and the like when the key is depressed, and outputs it as velocity data or after-touch data.

The switch detection circuit 6 includes a panel switch 9
It is provided corresponding to each operator (switch) provided in the, and outputs operation data according to the operation status of each operator as event information. Panel switch 9
Includes various operators for selecting, setting, and controlling automatic accompaniment start / stop, style, tone color of musical tone to be generated, volume, pitch, effect, and the like.

The tone generator circuit 7 is capable of simultaneously generating musical tone signals on a plurality of channels.
Of the performance data given via 3, data relating to the melody performance is input, and a musical tone signal relating to the melody is generated based on the input data. The mixer 10 inputs the musical tone signal regarding the melody from the tone generator circuit 7 and the musical tone signal regarding the chord performance or the bass performance from the automatic accompaniment device 4, and outputs a musical tone signal obtained by mixing the both to the sound system 11.

Any musical tone signal generating method may be used in the automatic accompaniment apparatus 4 and the tone generator circuit 7. 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 modulation calculation using the above address data as phase angle parameter data. And a known method such as an FM method for obtaining musical tone waveform sample value data or a method for performing a predetermined amplitude modulation calculation using the above address data as phase angle parameter data to obtain musical tone waveform sample value data. You may.

The tone signal mixed by the mixer 10 is converted into a digital-analog converter (AD) in the sound system 11.
C), sound is produced via an amplifier and a speaker. The timer 12 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 9. (Not shown). The generated tempo clock pulse is given to the CPU 1 as an interrupt command, and the CPU 1 executes various processes of automatic accompaniment by the interrupt process.

Next, an example of the processing of the chord detection device executed by the microcomputer will be described with reference to FIGS. 1, 3 and 4.
A description will be given based on the flowchart. 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 1 starts the processing according to the control program stored in the program memory 2. Then, in this "initial setting" processing, various registers and flags in the working memory 3 are initialized. Step 32: Scan the key-depression detection circuit 5 to operate the keyboard 8 to determine whether or not a key event has occurred,
If there is a key event (YES), the next step 33
If there is no key event (NO), go to step 3
Jump to 4.

Step 33 is a process performed each time the keyboard 8 is operated and a key event occurs. Details of this processing are shown in FIG. 4, and will be described later. Step 34: Scan the switch detection circuit 6 to operate the start / stop switch to determine whether an on event has occurred, and there is an on event (YES).
In case of NO, the process proceeds to the next step 35, and in case of no ON event (NO), the process jumps to step 39.

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 the next step 37, otherwise (NO), That is, when the automatic accompaniment is stopped, the process proceeds to step 38. 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,
Here, a start signal is output to the automatic accompaniment device 4. Step 38: 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, so the stop signal is sent to the automatic accompaniment apparatus 4. Is output. Step 39: It is determined whether or not there is an on event of the style selection switch on the panel switch 9. If there is an on event (YES), the process proceeds to the next step 3A, and if not (NO), the process jumps to step 3C. Step 3A: The style number of the performance selected by the style selection switch is stored in the style register STYL. Style means rock, waltz, bossa nova,
It is a performance style that follows various rhythms such as march and samba.

Step 3B: Style register STYL
The tone color of each part of the performance style corresponding to, along with the channel number corresponding to each tone color
Output to. Step 3C: Various processes such as a process based on the operation of other operators on the panel switch 9 and other volume changing processes are performed.

FIG. 4 is a diagram showing an example of the key event process of step 33 of FIG. 3 processed by the microcomputer. This key event process is sequentially executed in the following steps every time the keyboard 8 is operated and a key event occurs.

Step 41: It is judged whether or not the key event is the key-off event, and the key-off event (YES)
If No, the process proceeds to Step 42. If not (NO), the process proceeds to Step 4A. Step 42: Since the key-on event is determined in the previous step 41, the key code corresponding to the key-on event is stored in the key code register KC. Step 43: The tone generation processing (key-on processing) of the key code corresponding to the key-on event is performed.

Step 44: The key code stored in the key code register KC is transferred to the Nth list register L.
Store in IST (N). Here, N is the value stored in the variable register, and this value indicates the number of keys that are currently in the key-on state (the number of pressed keys). Therefore, every time there is a key-on event, it is incremented in step 45,
Conversely, each time there is a key-off event, decrement processing is performed in step 50.

Step 45: The variable register N is incremented by 1. As a result, the current number of pressed keys is stored in the variable register N. Step 46: Clear the data in the key code buffer BF, store the key code stored in the list register LIST (i) in the key code buffer BF (i), and return. That is, each time a key-on event occurs, the data in the key code buffer is rewritten to the key code currently being pressed.

Step 47: Since the key-off event is determined in the previous step 41, the key code corresponding to the key-off event is stored in the key code register KC. Step 48: Mute processing (key-off processing) of the key code corresponding to the key-off event is performed.

Step 49: List register LIST
The key code corresponding to the key-off event, that is, the key code stored in the key code register KC in step 47 is searched and deleted from (0) to LIST (N-1). Then, the list register LI generated by the deletion
In order to eliminate the ST empty area, the key code after this is packed forward. Step 48: List register LI from previous step 49
Since the key code has been deleted from ST, the variable register N is decremented by 1 in accordance with it, and the process returns.

FIG. 1 is a diagram showing a timer interrupt process executed by 96 interrupts per bar. In this process, chord detection control is performed. This process is sequentially executed in the following steps. Step 21: It is judged whether or not the performance running state flag RUN is "1", and if "1" (YES), that is, if automatic accompaniment is started, proceed to the next step 22, otherwise (NO), That is, the process returns when the automatic accompaniment is stopped. Step 22: Key code buffer BF (0) to BF
The key codes stored in (N-1) are sorted (sorted) in ascending order of sound, and the sorted results are stored in sort registers SRT (0) to SRT (N-1).

Step 23: Key code buffer BF
When the number of key codes stored in (i) is four, a chord is detected based on the four key codes stored in the sort registers SRT (0) to SRT (3).
When the number of key codes stored in the key code buffer BF (i) is 4 or less,
Sort registers SRT (0) to SRT (2), SRT
A chord is detected based on the key code in (0) to SRT (1) or SRT (0). The number of key codes is 2
In the case of one or one, the chord type is detected based on the previously detected chord.

Step 24: It is judged whether or not the chord detection is completed, that is, whether or not the chord can be detected by the process of the previous step 23. If the chord detection is completed (YES), the process proceeds to the next step 25. Proceed, and if not completed (NO), return. That is, there is a case where the chord cannot be detected based on the combination of the key codes in the sort register SRT (i), and in that case, the process immediately returns. Step 25: Root register R of the detected root of the chord
The stored chord type is stored in T and the detected chord type is stored in the chord type register TP. Step 26: Output the types of root note and chord stored in the root note register RT and the chord type register TP to the automatic accompaniment apparatus 4. As a result, the automatic accompaniment device 4 performs accompaniment based on the detected chord.

FIG. 5 is a diagram for explaining the operation of the chord detection device according to this embodiment, in which the horizontal axis represents time and the vertical axis represents the key depression state, that is, the number of keys depressed. FIG. 5A shows a case where the first loading time t1 is reached during the key depression and the second loading time t2 is reached during the key depression. FIG. 5B shows a case where the first key-in time t1 is reached in the middle of key depression, and all keys are released before the second key-in time t2.
FIG. 5C shows a case where key depression and key release are performed between the first loading time t1 and the second loading time t2. In (d) of FIG. 5, the first take-in time t1 is reached in the middle of key depression, key depression and key release are performed between the first take-in time t1 and the second take-in time t2, and the peak number of key depressions is 2 The case where it occurs in one place is shown.

First, FIG. 5A will be described. In FIG. 5A, time t before the first capture time t1
A key press (key-on event) occurs from 0, and the number of key presses gradually increases. In response to this key depression, steps 41 to 46 of the key event process of FIG. 4 are repeatedly executed, and the contents of the key code buffer BF (i) are rewritten every time the key is depressed. At this time, when the first fetch time t1 is reached while the number of key depressions is 3, the interrupt process of FIG. 1 is executed. In the key code buffer BF (i), the three latest key codes rewritten by the third key depression are stored, so in the interrupt processing of FIG. 1, chords are generated based on these three key codes. Is detected.

Even after the first fetching time t1, steps 41 to 46 of the key event process of FIG. 4 are repeatedly executed in response to a key press. In this example, the state of five key presses is still maintained. The interrupt process of FIG. 1 is also executed at the second fetch time t2. This time, since the five latest key codes rewritten by the fifth key depression are stored in the key code buffer BF (i), FIG.
In the interrupt processing of, chord detection processing is performed based on these five key codes.

When the key release event (key-off event) starts at time ta, steps 47 to 4A of FIG. 4 are repeatedly executed and stored in the list register LIST (i) corresponding to the previous key depression. The key code is deleted one after another, and the key code does not exist in the list register LIST (i). And next key press (key on)
When a new key code is generated, a new key code is stored in the list register LIST (i), and the chord detection process is executed at a predetermined time, that is, at each fetch time.

Next, FIG. 5B will be described. In FIG. 5B, a key depression (key-on event) occurs from time t0 before the first acquisition time t1, and the number of key depressions gradually increases. In response to this key depression, steps 41 to 46 of the key event process of FIG. 4 are repeatedly executed, and the contents of the key code buffer BF (i) are rewritten every time the key is depressed. At this time, when the first take-in time t1 is reached in the middle of pressing three keys, the interrupt process of FIG. 1 is executed as in the case of FIG. 5A, and the chord detection process is performed based on the three key codes. Is done.

Even after the first fetching time t1, steps 41 to 46 of the key event process of FIG. 4 are repeatedly executed in response to a key press. In this example, the key release (key-off event) starts at time tb before the second acquisition time t2, and the key release of all keys ends before the second acquisition time t2.
Then, steps 47 to 4A of FIG. 4 are executed in response to this key release, the corresponding key codes are deleted from the list register LIST (i) one after another, and the second fetch time t2.
At the time of, there is no key code in the list register LIST (i).

However, in this embodiment, all the key codes that are in the key-depressed state at the time of the last key depression that occurs between the first fetch time t1 and the second fetch time t2 are the key code buffer BF (i). Since it is already stored in
Even if the interrupt process of FIG. 1 is executed at the fetch time t2, the chord detection process is performed based on the five key codes stored in the key code buffer BF (i).

Next, FIG. 5C will be described. In (c) of FIG. 5, a key depression (key-on event) occurs at time tc after the first loading time t1 and all keys are released before the second loading time t2. Therefore,
In this case as well, all the key codes in the key-depressed state at the time of the last key depression are already stored in the key code buffer BF (i), so that the interruption process of FIG. Even if executed, the chord detection process is performed based on the five key codes stored in the key code buffer BF (i).

Next, FIG. 5D will be described. In FIG. 5D, time t before the first capture time t1
A key press (key-on event) occurs from 0, and the number of key presses gradually increases. In response to this key depression, steps 41 to 46 of the key event process of FIG. 4 are repeatedly executed, and the contents of the key code buffer BF (i) are rewritten every time the key is depressed. At this time, when the first fetch time t1 is reached in the middle of pressing three keys, the interrupt process of FIG. 1 is executed as in the case of FIG. 5 (a), and is stored in the key code buffer BF (i). Chord detection processing is performed based on the three key codes that are present.

In this example, two key-releases (key-off events) occur after time td1, so steps 47 to 4A in FIG. 4 are executed in response to the key-releases, and the list registers LIST (i) to 2 The key code corresponding to this key release is deleted.

However, since the key depression occurs again at time td2, steps 42 to 46 of the key event processing of FIG. 4 are executed in response to this key depression, and the key code buffer BF (i) is stored in the key code buffer BF (i). The latest four key codes are stored. Then, the key release is started again at time td3, and all rights are in the key release state before the second acquisition time t2. Therefore, after the time td3, steps 47 to 4A of FIG. 4 are executed, all the key codes corresponding to the key release are deleted from the list register LIST (i), and the list register LIST (i) is deleted at the second fetch time t2. There is no data inside.

That is, in this example, since the contents in the key code buffer BF (i) are rewritten corresponding to the key depression at time td2, the latest key depression as the key code is made in the key code buffer BF (i). The key code corresponding to the peak part is stored. Then, the second acquisition time t2
Then, the interrupt process of Fig. 1 is executed, and the key code buffer BF
The chord detection process is performed based on the four key codes stored in (i).

In the above-described embodiment, the case where chord detection is performed for all key events without determining which region of the keyboard has been described. However, the right key region and the left key region are separated by a predetermined key on the keyboard 8. Dividing into the keyboard range, the right keyboard performance operation corresponds to the performance of a melody, the musical tone of the corresponding pitch is controlled without detecting the chord, and the left keyboard performance operation corresponds to the chord performance. Alternatively, the chord may be detected based on the corresponding performance data.

Although the electronic musical instrument has been described in the above embodiment, the sequencer module for performing the automatic accompaniment process and the tone generator module including the key-depression detection circuit and the tone generator circuit are separately configured, and the data between the modules are separately arranged. It is needless to say that the same can be applied to a device configured to perform the transmission and reception of the known MIDI standard.

In the above-described embodiment, the chord is detected even when the take-in time is reached during the key depression, but when the take-in time is reached during the key depression, the chord is detected. The chord may be detected corresponding to the key depression only when the time during which the key state does not change is a predetermined time, for example, about 1/4 or more of the take-in time interval. By doing so, in the case of FIG. 5A, the chord detection process is not performed at the first loading time t1, but the chord detection process is performed at the second loading time t2, and during the key depression. There is no need to detect chords. For example, when the keys are pressed in the order of “do”, “mi”, “so”, and “shi”, the third key is pressed, that is, “do”, “mi”, and “so”.
If a chord is detected on the basis of, the chord is erroneously determined to be a C major, and it becomes difficult to detect the chord accurately. By seeing, it becomes possible to detect a chord at the next fetching time, and to detect an accurate chord called C Seventh based on “do”, “mi”, “so”, and “shi”.

Further, in the above embodiment, when there are two or more peaks of the number of key presses within the predetermined time as shown in FIG. 5D, the key press data corresponding to the latest peak is used. Although the case of detecting a chord has been described, the present invention is not limited to this, and the chord may be detected based on the key depression data corresponding to the peak of the peak portion having the longest maintenance time within the predetermined time. Furthermore, a chord may be detected for each peak and the detected one or the one with higher priority may be set.

[0047]

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 flowchart showing details of timer interrupt processing executed by interruption of 96 times per bar.

FIG. 2 is a hardware block diagram showing an embodiment of an electronic musical instrument incorporating the chord detection device 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 details of a key event process of FIG.

FIG. 5 is a diagram for explaining the operation of the chord detection device according to this embodiment.

[Explanation of symbols]

1 ... CPU, 2 ... Program memory, 3 ... Working memory, 4 ... Automatic accompaniment pattern memory, 5 ... Key detection circuit, 6 ... Switch detection circuit, ... Keyboard, 7 ... Sound source circuit, 8
... keyboard, 9 ... panel switch, 10 ... digital-analog converter, 11 ... sound system, 12 ... timer, 1
3 ... Data and address bus

Claims (1)

[Claims] 1. Input means for inputting performance data generated in response to a performance, key-depression state detection means for detecting a key-depression state within a predetermined time based on the performance data, and performance from the input means. The key-depression state detected by the key-depression state detecting means and the performance data corresponding to the key-depression state at each of the predetermined times which are set periodically based on a predetermined reference time signal regardless of the data input time. And a chord detecting means for detecting a chord based on