JP2002268637A - Meter deciding apparatus and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a meter deciding apparatus which automatically decides the meter of playing from playing data indicating the contents of the playing. SOLUTION: A user assigns the playing data stored by a file system in an FD 110 across an input device 108 and instructs the meter decision of the playing indicated by the same. When this decision is instructed, a CPU 101 acquires the assigned playing data by having this data read out of the FD 110. The CPU forms note strings which are the list of the notes, extracts the partial note strings coincided with the other part and specifies the playing time of one measure by noticing the extracted partial note strings. Thereafter, the CPU divides the note strings to a one measure unit by the playing time of the specified one measure and decides the meter on the basis of the note string of the one measure obtained in the manner described above and displays the result of the decision on an LCD 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for automatically determining the time signature of a performance from performance data representing the content of the performance.

[0002]

2. Description of the Related Art At present, an automatic reproduction apparatus for automatically reproducing performance data for performance reproduction has been commercialized. With the automatic playback device, even one user can enjoy a way of enjoying like an ensemble performance.

[0003] Usually, performances are performed along a basic musical time called a time signature. For this reason, it is necessary for the user (performer) to perform while paying attention to the beat. Therefore, when performing an ensemble with a performance (including an accompaniment or the like) performed by the automatic playback device, notifying the time signature of the performance has a significant meaning in enabling the user to perform the performance more appropriately. It is thought that there is.

Conventionally, the time signature can be notified by preparing data indicating the time signature (hereinafter referred to as time signature data) in advance. For this reason, in the case of performance data for which the time signature data has not been prepared, the time signature of the performance cannot be notified to the user. From this, to be able to tell the time signature even without that data,
It has been desired to realize a time signature determination device that automatically determines the time signature.

It is an object of the present invention to provide a time signature judging device for automatically judging the time signature of a performance from performance data representing the content of the performance.

[0006]

The time signature determining apparatus of the present invention is based on the premise that the time signature of the performance is automatically determined from the performance data representing the content of the performance, and the performance data obtaining means obtains the performance data. And a note sequence generating means for generating a note sequence which is a sequence of notes of the performance represented by the performance data from the performance data obtained by the performance data obtaining means, and a note sequence from the note sequence generated by the note sequence generating means. A partial note string extracting means for extracting a partial note string whose arrangement matches another part, and a performance of one measure based on the playing time of the partial note string extracted by the partial note string extracting means and its position. A performance time specifying means for specifying a time, and a note sequence divided into one bar unit by the performance time of one measure specified by the performance time specifying means, and a time signature is obtained based on the unit note sequence obtained by dividing the note sequence. Time signature to judge Comprising a means, a.

The time signature judging means extracts a unit note sequence in which the note at the top of the unit note sequence has a strong beat, and judges the time signature based on the extracted unit note sequence. It is desirable. A program according to the present invention is a program to be executed by a device for automatically determining the time signature of a performance from performance data representing the content of a performance, the function of acquiring performance data, and the performance data acquired by the acquiring function. A function of generating a note sequence that is a sequence of notes of the performance represented by the performance data, and extracting a partial note sequence in which the sequence of notes matches another portion from the note sequence generated by the generating function. Based on the playing time of the partial note string extracted by the extracting function and the position thereof,
A function of specifying the performance time of a measure, and a note sequence is divided into one bar unit by the performance time of one measure specified by the specifying function, and a time signature is obtained based on the unit note sequence obtained by dividing the one note unit. And a determination function.

According to the present invention, a note sequence which is a sequence of notes of a performance represented by the performance data is generated, and a partial note sequence having a sequence of notes matching other portions is extracted from the note sequence. Then, based on the performance time of the extracted partial note sequence and its position, the performance time of one measure is specified, and the note sequence is divided into one measure unit by the specified performance time of one measure.
The time signature is determined based on the unit note sequence obtained by dividing the bar into bars.

[0009] In most cases, a beat that produces a time signature is established by combining notes of different note values. Since the time signature is set as an immovable cycle, the same combination of notes (arrangement of notes) appears in measures during a performance.
From this, by paying attention to the partial note sequence in which the sequence of notes matches other parts, the playing time for one measure, ie, 1
It becomes possible to specify the note sequence of a bar and its position.

The time signature is perceived by the listener by sensing a constant beat and period (corresponding to the performance time of one bar) in the rhythm. This means that the period and the beat pattern are different depending on the time signature. By specifying the note sequence of one measure and its position, it is possible to divide the note sequence in units of one measure. Therefore, the time signature can be determined on the basis of the unit note sequence obtained by dividing into one bar unit.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a circuit configuration diagram of the time signature determination device according to the present embodiment. FIG.
As shown in FIG. 1, the time signature determination device includes a CPU 101 that controls the entire device, and a ROM 1 that stores programs executed by the CPU 101 and various control data.
02 and RAM used by the CPU 101 for work
103, a chanting display (LCD) 104 for displaying information to be displayed to the user, a floppy disk device (FDD) 105 for accessing a floppy disk (FD) 110 in accordance with instructions from the CPU 101, and A speaker 106 to be used, a sound source 107 that generates musical sound waveform data in accordance with an instruction from the CPU 101, converts the waveform data into an analog audio signal, and outputs the analog audio signal to the speaker 106, and an input device 108 operated by a user. It is provided with. Input device 10
4 is a keyboard, for example.

The time signature judging device having the above-mentioned structure is provided by the FD
The present invention is implemented as a device that determines the time signature of the performance represented by the performance data stored as a file in the file 110 and notifies the user of the determined time signature by the LCD 104. In the present embodiment, as the performance data, data for automatic reproduction such as a standard MIDI file (SMF) is assumed. Note that the performance data may be image data for displaying a musical score or the like, instead of data for automatic reproduction. Also, it is not limited by a format or the like.

When the power is turned on, the CPU 101 reads out and executes a program stored in the ROM 102 to start control of the entire apparatus. The control is performed in a form corresponding to an instruction given by the user via the input device 108. The instruction is sent from the CPU 101 to the LCD.
The information to be notified to the user is displayed on the display 104 at any time, so that the information can be interactively displayed. LCD1
Display of information on the display 04 is realized, for example, by the CPU 101 reading image data for display from the ROM 102 according to the information to be displayed, and outputting the read image data or image data obtained by processing the read image data to the LCD 104. .

For the determination of the time signature, the user operates the input device 108 to specify, for example, performance data (a file stored in the FD 110) for which the time signature is to be determined, and then instructs execution of the time signature determination. It is done by that. CPU
101, when execution of the time signature determination is instructed, first, the FD
FDD file (performance data) specified in 110
The file 105 is read, and the read file is received and written to the RAM 103. After that, the RAM 103
Then, an analysis is performed to identify the time signature of the contents of the performance of the file written in, and the time signature determined thereby is displayed on the LCD 104. The details will be described later.

On the other hand, in the automatic reproduction of performance data, the user operates the input device 108 to specify, for example, performance data (file stored in the FD 110) to be automatically reproduced, and then instructs the automatic reproduction. It is done by that. C
When the execution of the automatic reproduction is instructed, the PU 101 first causes the FDD 105 to read the file (performance data) specified in the FD 110, as in the case of the time signature determination, receives the read file, and receives the read file. Write to. The performance data is, for example, data obtained by adding time data representing the processing timing to each event data representing the content of an event in the performance. Therefore, the CPU 101 reproduces event data by sequentially processing the event data from the beginning of the performance data written in the RAM 103 in accordance with the time data added thereto. The processing of event data depends on the event data,
Alternatively, it is performed by transmitting a command corresponding to the command to the sound source 107. When the CPU 101 performs such processing, a musical sound is emitted from the speaker 106 in accordance with the progress of the processing on the performance data.

FIG. 2 is a flowchart of the time signature determination process. That is, when the user operates the input device 108 to instruct the user to execute the time signature determination for the specified performance data (file), the process is executed to determine the time signature of the performance represented by the performance data. It is. Next, FIG.
, The time signature determination process will be described in detail. The time signature determination process is performed, for example, by the CPU 101
Is realized by reading and executing a program stored in the ROM 102.

First, in step 201, a file (performance data) designated by the user is
The data is read from 105 and stored in the RAM 103. In the following step 202, focusing on the event data constituting the performance data stored as a file in the RAM 103 and the time data added to the event data, the types of notes forming the performance represented by the performance data and the arrangement thereof are determined. By specifying, a note sequence that is a sequence of notes is generated. Thereafter, the process proceeds to step 203.

For example, in MIDI, as is well known, the resolution (the number of clocks per quarter note) is 24, and the time data is represented by the resolution. From this,
In MIDI, the type of musical note can be specified by calculating the number of clocks from the start of sound generation to silence for each pitch.

By the way, as is well known, performance usually has fluctuation. If the fluctuation is reflected in the generation of the note sequence, the processing content becomes complicated. For this reason, in the present embodiment, the type of note and its position are specified by rounding with a performance time that is a predetermined unit (hereinafter referred to as a unit performance time). The unit performance time is, for example, a time corresponding to a 32nd note. The notes include notation indicating a sounding time of a musical tone to be sounded, such as a quarter note and an eighth note, and rests indicating time not to be sounded, such as a quarter rest and an eighth rest. For a musical note representing a musical tone to be pronounced, a velocity value indicating the volume is extracted from the event data.

In step 203, from the generated note sequence, the arrangement of notes matches other parts, that is, the kind of notes and their order match other parts, and the total playing time is a predetermined playing time. Extract the partial note sequence that is longer than the time. In the next step 204, analysis is performed focusing on the position of the extracted partial note string (the position in the note string) and the performance time thereof, and the performance time of one measure and the break of measure are specified. The process proceeds to step 205 after specifying them. The predetermined performance time is, for example, a time corresponding to one measure of 3/8 time. The note string generated in step 202 will be hereinafter referred to as a whole note string to avoid confusion.

The performance time of one measure and the break of a measure (1
The position of the note sequence in a bar is determined by specifying a note sequence (unit note sequence) in one bar as follows. A specific description is given with reference to FIG. The score examples 1 to 3 shown in FIGS. 3 (a) to 3 (c) respectively show and extract the arrangement of notes in an actual song. Vertical lines represent bar lines. Here, in order to specify each bar separated by a vertical line representing a bar line, the number of the bar located at the beginning of the bar is set to 1
Then, two or more numbers are sequentially assigned to the following bars.

As is well known, in modern music, the time signature is set as an immovable period, and the rhythm is created in relation to the rhythm (the structure of the beat in one bar) which is the source of the time signature. In most cases, the rhythm is established by combining notes of different note values in order to avoid being monotonous. For this reason, in the present embodiment, the performance time of one measure and its delimiter are specified by focusing on the partial note sequence in which notes having different note values are arranged. In addition,
It is known that when the sound value is changed, the weight tends to be felt as the length increases.

In the first example, as shown in FIG.
The arrangement of notes in the third measure and the third measure is the same. Otherwise, the arrangement of twelve sixteenth notes in each of the first to third measures matches. They have a somewhat long overall playing time. For this reason, by executing the processing of step 203, they are extracted as partial note strings, but there is no change in the note value in the sequence of twelve sixteenth notes. For this reason, in the example 1, the arrangement of the notes in the second (3) th measure is specified as a note sequence of one measure. As a result, the performance time of one measure is a time corresponding to eight eighth notes, and the whole note sequence is divided by the performance time of one measure with reference to the second or third measure. This is the same in the example 2 shown in FIG.

In the third example, as shown in FIG. 3 (c), the arrangement of notes having a change in note value coincides not only in the first bar and the fifth bar, but also in the second bar and the sixth bar. The third, seventh, and seventh match. This means that the sequence of notes formed in the first to third measures is extracted as a partial note sequence.

In order to cope with such a situation, in the present embodiment, the upper limit of the performance time for one measure is determined, and not only the partial note sequence but also the portion interposed therebetween is noted. ing. For example, if the playing time of a partial note string is divisible by the playing time of a note string between two partial note strings, the note string of that part is regarded as a one-measure note string. I have. For this reason, in the example 3, the arrangement of the notes in the fourth measure sandwiched between the third measure and the fifth measure is specified as a note sequence of one measure.

The performance time of one measure and its division are basically performed by the method described above.
However, a note sequence of one measure cannot always be extracted (specified) by such a method. From this,
In practice, verification is also performed by paying attention to the relationship between the extracted partial note strings or the playing time between the note strings in a portion interposed therebetween. As a result, a note sequence of one measure can be extracted with higher accuracy.

The verification means, for example, whether or not the playing time of each partial note string is divisible by the playing time of one of the partial note strings or the time obtained by dividing the time difference between them by one or more integers. It is to be. In such a verification, in the example 2 of FIG. 3B, the performance time of the note string coincides with the first and second measures, and the performance time is sandwiched between the second and fourth measures. This is done in a manner that confirms that it also matches the third measure. In the example 3 of FIG.
As a result of such verification, the note sequence of the fourth measure is 1
It is extracted as a note sequence of measures.

As described above, in step 205 where the performance time of one measure and the division of a measure, that is, the note sequence of one measure and its position are specified, the transition is made to the performance of one measure based on the position. By dividing by time, the whole note sequence is divided into one bar units, and a note sequence (unit note sequence) used for time signature determination is extracted from a one bar note sequence.
In the next step 206, a change in velocity (note volume) and a focused analysis of notes are performed on the extracted one-note note sequence (unit note sequence) to determine the time signature. Step 20 to go to after determining the time signature
At 7, the determined beat is displayed on the LCD 104.
A series of processing ends thereafter.

Here, the processing performed in steps 205 and 206 will be described in more detail. It is known that “instability” (tension) exists as an element that generates the progress of music, and that most music (performance) has transitions between “stable” and “unstable”. Such a musical structure is to maintain the interest and interest while gaining the listener's understanding.

The transition between "stable" and "unstable" in music is summarized in the tonality and the pulsation of the beat. “Stable-unstable” seen in the time signature is usually a swing motion centered on the time signature presented by the time signature. The swinging motion means that the positions of the strong beat and the weak beat in the bar are not always constant. From this, in order to prevent the swinging motion from affecting the time signature determination, in step 205, the velocity value (volume) of the note located at the beginning of the note sequence of one measure (unit note sequence) Are extracted, that is, those in which the strong beat is placed on the first beat. Unit note strings whose velocity values monotonically increase or decrease are also excluded from the target of extraction.

The above-mentioned rhythm is used to change a sequence of sounds into an orderly moving body, and a continuous period of the rhythm is a time signature. Within a bar, the first beat is positioned at the beginning and end of the cycle, and the other beats are aimed at the first beat. The first beat, which is the starting point of the cycle, is the strongest,
The back beat is the weakest. From this, the rhythmic structure of the bar where the strong beat is not placed on the first beat is in an “unstable” state,
That is, it is considered that the time signature does not correspond to the time signature indicated by the time signature. Therefore, the accuracy of the determination can be improved by not using the note sequence of such a bar for the time signature determination.

It is known that the velocity change within a bar, that is, the flow of energy, differs depending on the time signature. As shown in FIGS. 4A to 4E, the velocity change also changes depending on the type of note used and its arrangement. FIGS. 4A to 4E show examples by time signature and by type of musical note used. FIG.
(A) shows the velocity change (the flow of energy) in 3/4 beats that frequently use quarter notes. Less than,
Similarly, FIG. 4 (b) is a 3/4 time signature that frequently uses eighth notes, FIG. 4 (c) is a 4/4 time signature that frequently uses quarter notes, and FIG. 4 (d).
FIG. 4E shows a change in velocity in a ／ time signature that frequently uses eighth notes, and FIG. 4E shows a change in velocity in a 6/8 time signature that frequently uses eighth notes.

As shown in FIGS. 4A to 4E, the change in velocity forms a unique pattern depending on the time signature and the type of note (note value). In FIGS. 4A to 4E, all the notes have the same note value, but in practice, notes with different note values are almost always combined as described above. Also, the pattern does not always appear in all measures in which the first beat is a strong beat. For this reason, in the present embodiment, the unit note string (1
At least one pattern of velocity change that is average or most frequently occurring in a note sequence of bars is extracted in consideration of the type of note and its arrangement.

The extracted pattern is compared with a velocity change pattern prepared as data in the ROM 102. Thereby, the most similar pattern among the patterns prepared in the ROM 102, at least the pattern in which the position and the number of accents in the measure match, is specified.
It is determined that the time signature of the specified pattern is the time signature of the performance represented by the performance data. In order to reduce the processing time, among the patterns prepared in the ROM 102, those which do not match the specified one bar performance time are excluded from comparison.

Even if the time signature is determined in this manner, since the velocity change pattern has a unique shape depending on the time signature, the time signature can be accurately determined. In the time signature determination, a unit note sequence that may deviate from the original pattern is excluded. Thereby, the time signature can be determined more accurately.

In the present embodiment, the time signature determination result is displayed on the LCD 104, but the determination result may be simply output to an external device.
The performance data is acquired by the FDD 105 accessing the FD 110, but may be acquired by accessing another medium or an external device.

In the present embodiment, the present invention is applied to a device having an automatic reproduction function, but the device to which the present invention can be applied is not limited to such a device. The present invention can be widely applied to various devices. For example, a program for realizing the above operation is RO
M, CD-ROM, floppy (registered trademark) disk,
Alternatively, it may be recorded on a recording medium such as a magneto-optical disk and distributed. Alternatively, part or all of the program may be distributed via a transmission medium used in a public network or the like. In such a case, the user can acquire the program and load it into a time signature determination device or a data processing device such as a computer, so that the present invention can be applied to the loaded device.

[0038]

As described above, according to the present invention, a note sequence which is a sequence of notes of a performance represented by the performance data is generated from the performance data. The extracted partial note sequence is extracted, the performance time for one measure is specified based on the performance time of the extracted partial note sequence, and the position thereof, and the note sequence is specified by the specified performance time for one measure.
The time signature is determined on the basis of a unit note string obtained by dividing the bar into bars.

In most cases, a rhythm that produces a sense of time is established by combining notes of different note values. Since the time signature is set as an immovable cycle, the same combination of notes (arrangement of notes) appears in measures during a performance.
Therefore, by paying attention to the partial note sequence in which the sequence of notes matches other portions, it is possible to specify the performance time of one measure, that is, the note sequence of one measure and its position.

The beat is perceived by the listener by sensing a constant beat and period (corresponding to the performance time of one bar) in the rhythm. This means that the period and the beat pattern are different depending on the time signature. By specifying the note sequence of one measure and its position, the note sequence can be divided into one measure unit. For this reason, the time signature can be determined based on the unit note sequence obtained by dividing into one bar unit.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of a time signature determination device according to the present embodiment.

FIG. 2 is a flowchart of a time signature determination process.

FIG. 3 is a diagram for explaining a method of specifying a performance time of one measure.

FIG. 4 is a diagram illustrating a change in velocity within a bar.

[Explanation of symbols]

 101 CPU 102 ROM 103 RAM 104 LCD 105 Floppy disk device 108 Input device 110 Floppy disk

Claims (3)

[Claims] 1. An apparatus for automatically determining a time signature of a performance from performance data representing the content of a performance, wherein the performance data obtaining means obtains the performance data, and wherein the performance data obtaining means obtains the performance data. Note string generating means for generating, from the performance data, a note string which is a sequence of notes of the performance represented by the performance data; and, from the note string generated by the note string generating means, the arrangement of the notes is identical to that of another part. A partial note string extracting means for extracting a matched partial note string, a playing time of the partial note string extracted by the partial note string extracting means, and a playing time for specifying a playing time for one measure based on the position thereof. Specifying means; dividing the note string into one-measure units based on the performance time for one measure specified by the performance time specifying means; and determining a time signature based on a unit note string obtained by dividing the note string into one measure units means , Time signature determination apparatus characterized by comprising a. 2. The time signature judging means extracts a unit note sequence in which a note located at the beginning of the unit note sequence has a strong beat, and judges the time signature based on the extracted unit note sequence. The time signature judging device according to claim 1, wherein 3. A program to be executed by an apparatus for automatically determining the time signature of a performance from performance data representing the content of a performance, the program comprising: a function of acquiring the performance data; From the performance data,
A function of generating a note sequence that is a sequence of notes of the performance represented by the performance data; and extracting a partial note sequence in which the sequence of notes matches another portion from the note sequence generated by the generating function. A function for specifying a performance time for one measure based on a performance time of a partial note string extracted by the function for extracting and a position thereof, and a performance time for one measure specified by the function for specifying A program for realizing a function of dividing the note sequence into one bar units and determining a time signature based on a unit note sequence obtained by dividing the note sequence in one bar units.