JP2006106313A - Chord discrimination device and chord discrimination processing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a chord discrimination device for exactly discriminating a chord. <P>SOLUTION: Since chord discrimination is performed by excluding notes of tone lengths shorter than a predetermined tone length from among individual notes constituting music data MD and detecting a note name for each chord discrimination period on the basis of the other notes, exact chord discrimination can be carried out without including passing notes and ornaments notes in the object of the chord discrimination. Also, even in a case of a note shorter than the predetermined tone length, when a note produced at the same time as that note is present, chord decision is made without excluding the note shorter than the predetermined tone length, therefore, a chord of a short tone length such as staccatos can be detected, and exact chord discrimination becomes possible. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a code determination apparatus and a code determination processing program suitable for use in, for example, a sequencer.

  There is known an apparatus for determining a code for music data representing each sound constituting a music. As this type of device, for example, in Patent Document 1, a chord determination is made every time there are a plurality of notes having the same mute timing, or whether there are two or more notes for each beat timing is present. In such a case, a chord is determined for each beat based on the note names of those notes.

JP 2000-259154 A

  By the way, in the apparatus disclosed in the above-mentioned Patent Document 1, since all the sounds in the chord judgment range are set as chord judgment target sounds, for example, sounds that are originally unnecessary for chord judgment, such as elapsed sounds and decorative sounds, are used. However, as a result of being included in the code determination target, an inaccurate code determination is rarely performed.

  Therefore, the present invention has been made in view of the above-described circumstances, and an object thereof is to provide a code determination device and a code determination processing program that can perform accurate code determination.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a storage means for storing each sound constituting a song, and a sound having a sound length shorter than a predetermined sound length among the sounds stored in the storage means. And a chord determination means for determining chords for each chord determination section based on other sounds.

  In the invention according to claim 2 subordinate to claim 1, the chord determination means, if the sound read from the storage means is shorter than a predetermined sound length, outputs another sound that is pronounced simultaneously with the read sound. A search is made from the storage means, and when there is a corresponding sound, a chord determination is made without excluding a sound having a sound length shorter than the predetermined sound length.

  In the third aspect of the present invention, storage means for storing each sound constituting the music, setting means for setting a chord determination section, and setting a specific sound length corresponding to the set chord determination section, For each chord determination section set by the setting means based on other sounds, excluding sounds having a shorter sound length than the specific sound length set by the setting means from among the sounds stored in the storage means And a code determining means for determining a code.

  According to the fourth aspect of the present invention, each sound constituting the music is stored, a sound having a shorter sound length than the predetermined sound length is excluded from the stored sounds, and the chord is based on the other sounds. A code determination process for determining a code for each determination section is executed by a computer.

  In the invention according to claim 5, which is dependent on claim 4, the chord determination processing is performed such that when the sound read from each stored sound is shorter than a predetermined sound length, the sound is simultaneously generated with the read sound. The sound is searched from the stored sounds, and if there is a corresponding sound, the chord determination is performed without excluding the sound having a shorter sound length than the predetermined sound length.

  In the invention according to claim 6, a storage process for storing each sound constituting the music, a setting process for setting a chord determination section and a specific sound length corresponding to the set chord determination section, Codes set in the setting process based on other sounds are excluded from the sounds stored in the storing process, excluding sounds having a shorter sound length than the specific sound length set in the setting process A code determination process for determining a code for each determination section is executed by a computer.

  According to the first and fourth aspects of the present invention, each sound constituting the music is stored, and a sound shorter than a predetermined sound length is excluded from the stored sounds, and other sounds are excluded. Therefore, the chord determination is performed for each chord determination section, so that it is possible to perform an accurate chord determination without including the elapsed sound or the decoration sound as a chord determination target.

  According to the second and fifth aspects of the present invention, if the sound read from each of the stored sounds is shorter than the predetermined sound length, other sounds that are pronounced simultaneously with the read sound are stored for each stored sound. If the corresponding sound exists, the chord is determined without excluding the sound having a shorter sound length than the predetermined sound length, so that a chord having a short sound length such as a staccato can be detected, and an accurate chord determination is performed. It can be performed.

  According to the third and sixth aspects of the invention, when a chord determination section and a specific sound length corresponding to the chord determination section are set, a sound having a sound length shorter than the specific sound length is excluded from the stored sounds. Based on the sound other than that, chord judgment is performed for each set chord judgment section, so that unnecessary sounds for chord judgment can be excluded according to the set chord judgment section, thereby making accurate chord judgment Can do.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
A. Configuration FIG. 1 is a block diagram showing an overall configuration of a code determination apparatus according to an embodiment of the present invention. The code determination apparatus shown in this figure includes a CPU 1, a ROM 2, a RAM 3, an operation unit 4, a display unit 5, and a MIDI interface 6. The CPU 1 controls each part of the apparatus in response to a switch event generated by the operation unit 4 and its characteristic processing operation will be described in detail later. The ROM 2 stores a code type determination table CTDT, which will be described later, in addition to various control programs loaded into the CPU 1. The various control programs referred to here include a main routine, pitch class extraction processing, chord processing, and chord determination processing described later.

The code type determination table CTDT stored in the ROM 2 is a table storing code pattern data for each code type ChordType [0] to [k], as shown in FIG. 2, and the code type specified by the pointer k. Code pattern data of ChordType [k] is generated.
The code pattern data is 12 sounds from CB to LSB from MSB to LSB (C, C #, D, D #, E, F, F #, G, G #, A, A #, B). , And a bit position corresponding to a chord constituent sound (pitch name) is set to “1”. For example, in the chord type ChordType [0], chord pattern data “100010010000” representing the chord constituent sounds “C (do)”, “E (mi)”, and “G (so)” of the chord type “major” is generated. It is like that.

The RAM 3 includes a work area and a data area. In the work area of the RAM 3, various register / flag data used for the processing of the CPU 1 are temporarily stored. On the other hand, the music data MD, the pitch class table PCT, and the determination codes Chord [0] to [n] are stored in the data area of the RAM 3.
The song data MD is MIDI format data supplied from the electronic musical instrument 7 via the MIDI interface 6. That is, as shown in FIG. 3, the music data MD is composed of events EventData [0] to [N] arranged in the order of music progress and data END representing the end of music. One event EventData has event timing Time expressed by an absolute time method, sound length GTime, event data Data indicating note on / off, note number Note, channel number CH, and velocity Vel.

As shown in FIG. 4, the pitch class table PCT stored in the data area of the RAM 3 includes a beat number (or measure number) x representing a chord determination section in beat units (or measure units), and C to B sounds. It consists of registers Pclass [x] [y] corresponding to pitch name numbers “0” to “11” corresponding to the twelve tones.
As will be described later, the CPU 1 stores the note-on event notes having a sound length GTime that is equal to or greater than a predetermined value (for example, eighth note length) for each chord determination section corresponding to the beat number (or measure number) x in the music data MD. The presence / absence of the corresponding note does not exist. If the corresponding note does not exist, “0” is set in the corresponding register Pclass [x] [y] in the pitch class table PCT. Then, “1” is set in the register Pclass [x] [y] of the pitch name number y corresponding to the pitch name of the note.

  Therefore, the pitch class table PCT represents the pitch names of the chord determination target sounds that exist for each chord determination section. For example, when the pitch class table PCT in the example shown in FIG. 4 represents a chord determination section in units of beats, “C sound” (register Pclass [1] [0]) and “D sound” (register Pclass [1] [0]) indicates that there is a chord determination target sound.

  Next, the configuration of the embodiment will be described with reference to FIG. 1 again. The operation unit 4 includes various operation switches and generates a switch event corresponding to a user's switch operation. Although not shown in the drawing, this operation unit 4 is, for example, a song selection switch for selecting song data MD for chord judgment, a section selection switch for setting whether the chord judgment section is in beat units or measure units, or the next A chord determination continuation switch for specifying whether or not to continue chord determination for music data is provided.

  In response to the display control signal supplied from the CPU 1, the display unit 5 displays, for example, music data MD for performing chord determination on a display screen, or displays the chord determination result for each chord determination section on the screen. indicate. The MIDI interface 6 exchanges music data MD in the MIDI data format with an external electronic musical instrument 7 under the control of the CPU 1. The music data MD fetched from the electronic musical instrument 7 via the MIDI interface 6 is stored in the data area of the RAM 3 described above.

B. Operation Next, the operation of the embodiment according to the above configuration will be described with reference to FIGS. In the following, after describing the operation of the main routine executed by the CPU 1 as a schematic operation, each operation of pitch class extraction processing, chord processing, and chord determination processing constituting the main routine will be described.

(1) Main Routine Operation When the apparatus power is turned on, the CPU 1 executes the main routine shown in FIG. 5 and proceeds to step SA1 to initialize various register / flag data provided in the work area of the RAM 3. Perform initialization processing. Next, at step SA 2, the music data MD is taken from the electronic musical instrument 7 via the MIDI interface 6 and stored in the data area of the RAM 3.
Subsequently, in step SA3, the elapsed sound and the decoration sound are excluded from the sounds constituting the music data MD, and the sound that is note-on with a predetermined length or longer is extracted as a chord determination target sound for each chord determination section. Then, a pitch class extraction process for registering the pitch name in the pitch class table PCT (see FIG. 4) is executed.

In step SA4, a code determination process for determining a code for each code determination section is performed with reference to the pitch class table PCT generated in the pitch class extraction process. Thereafter, the process proceeds to step SA5, and other processing such as, for example, displaying the score of the song data MD determined for chord or displaying the chord determination result on the screen along with the score display is executed.
Next, in step SA6, the process waits until a chord determination continuation switch that specifies whether or not to continue chord determination for the next song data is operated. When the switch is operated, the determination result is “YES”. The process returns to step SA2 described above. Thereafter, the above steps SA2 to SA5 are repeated, and the code determination is repeated for the next music data MD.

(2) Operation of Pitch Class Extraction Process Next, the operation of the pitch class extraction process will be described with reference to FIG. When this process is executed through step SA3 (see FIG. 5) of the main routine described above, the CPU 1 proceeds to step SB1 shown in FIG. 6, and the pointer i for designating the event EventData [i] of the song data MD and The pointer k designating the code determination section is reset to zero. In the present embodiment, since the code determination section is a measure, the pointer k represents a measure number.

  Next, in step SB2, it is determined from the music data MD stored in the data area of the RAM 3 whether or not there is an event EventData [i] corresponding to the pointer i. If there is an event EventData [i] corresponding to the pointer i, the determination result is “YES”, the process proceeds to Step SB3, and it is determined whether or not the event EventData [i] is a note-on event. Whether or not the event is a note-on event is determined by referring to the event data Data in the event EventData [i].

If the event data Data is other than a note-on event, the determination result is “NO”, and the process proceeds to Step SB7 described later. On the other hand, if it is a note-on event, the determination result is “YES”, and the flow proceeds to step SB4. In step SB4, it is determined whether or not the sound length GTime in the event EventData [i] is longer than the predetermined sound length STime. The predetermined tone length STime refers to a short tone length (for example, a sixteenth note length) such as a elapsed tone or a decoration tone. If the note length GTime of the note-on sound is longer than the predetermined tone length STime, the determination result is “YES”, and the flow proceeds to step SB5.
On the other hand, if it is shorter than the predetermined tone length STime, it may be a chord with a short tone length such as staccato, so the determination result is “NO”, and a chord process (described later) for detecting a chord via step SB6. Then, the process proceeds to step SB7.

  Next, in step SB5, the pitch name of the chord determination target sound that is note-on with a predetermined length or longer is registered in the pitch class table PCT. That is, “1” is set in the register Pclass [k] [Note mod 12] specified by the measure number indicated by the pointer k and the note name Note name (Note mod 12) in the event EventData [i]. . Note mod 12 represents a 12 remainder value of note number Note, and thereby a value corresponding to the pitch name is calculated.

In step SB7, the pointer i is incremented and stepped, and in the subsequent step SB8, whether or not the event timing Time in the event EventData [i] is smaller than the bar end time BarEnd, that is, exceeds the code determination section. Judge whether. If it does not exceed the code determination section, the determination result is “YES”, and the process returns to step SB2 described above.
On the other hand, if the code determination section is exceeded, the determination result is “NO”, the process proceeds to step SB9, the measure number of the pointer k is incremented, and then the process returns to step SB2.

Thereafter, the above steps SB2 to SB9 are repeated until the event EventData [i] of the music data MD designated by the pointer i reaches the data END indicating the music end. As a result, among the sounds constituting the music data MD, the names of the sounds excluding the elapsed sound and the decoration sound are registered in the pitch class table PCT for each chord determination section.
When the sound read from the music data MD according to the pointer i is a elapsed sound or a decoration sound shorter than a predetermined sound length STime (for example, 16th note length), as described above, the sound length such as staccato is used. Therefore, the chord is detected by the chord processing described later.

(3) Operation of Chord Processing Next, the operation of the chord processing will be described with reference to FIG. When this process is executed via step SB6 (see FIG. 6) of the pitch class extraction process, CPU 1 proceeds to step SC1 shown in FIG. 7, and the current event EventData [ i] is stored in the register TimeBuf. Subsequently, in step SC2, the pointer i set in the pitch class extraction process is stored in the register iNow.
Next, in steps SC3 to SC5, a note-on event having the same event timing Time as the current event is searched while the pointer i is incremented. That is, the sound that is pronounced simultaneously with the sound of the current event is searched after the current event. If a corresponding sound is found, the determination result in step SC5 is “YES”, and the flow proceeds to step SC10 described later.

  On the other hand, if no sound is generated simultaneously with the sound of the current event after the current event, the determination result in step SC4 is “NO”, the process proceeds to step SC6, and the current event saved and stored in the register iNow. Is set to the pointer i. Subsequently, in steps SC7 to SC9, a note-on event having the same event timing Time as the current event is searched while the pointer i is decremented. That is, the sound that is pronounced simultaneously with the sound of the current event is searched before the current event. If the corresponding sound is not found, the chord is not established, so the determination result in step SC8 is “NO”, and this process is completed.

  On the other hand, if a sound that is pronounced simultaneously with the sound of the current event is found before the current event, the determination result in step SC9 is “YES”, and the flow proceeds to step SC10. In step SC10, the note name (Note mod 12) of the sound that is generated simultaneously with the sound of the current event is registered in the pitch class table PCT. That is, “1” is set in the register Pclass [k] [Note mod 12] specified by the measure number indicated by the pointer k and the Note mod 12, and the process is terminated.

  As described above, in the chord processing, in the above-described pitch class extraction processing, for example, there is a sound that is pronounced simultaneously with the sound even if the sound is shorter than a predetermined sound length STime, which is regarded as a progress sound or a decoration sound. Is registered in the pitch class table PCT with the names of the sounds that can be generated simultaneously. Thereby, even a short chord such as a staccato can be detected.

(4) Operation of Code Determination Process Next, the operation of the code determination process will be described with reference to FIG. When this process is executed through step SA4 (see FIG. 5) of the main routine described above, the CPU 1 advances the process to step SC1 shown in FIG. 8 and resets the pointer i to zero. Next, in step SC2, the pitch names (registers Pclass [i] [0] to [11]) of the chord determination section designated by the pointer i among the pitch names registered for each chord section in the pitch class table PCT. Is read. Subsequently, in step SD3, the pointer k and the register Per are reset to zero and the initial value “−1” is stored in the buffer kBuf.

In step SD4, the code pattern data of the code type ChordType [k] specified by the pointer k is read from the code type determination table CTDT stored in the ROM 2, and the code pattern data and the register Pclass [i] read in the step SD2 are read. The coincidence rate with [0] to [11] is calculated.
The coincidence rate is the number of coincidence of bit positions where “1” is set in both the bit pattern and the code pattern data, assuming that the registers Pclass [i] [0] to [11] are 12-bit bit patterns. This is divided by the total number of pitch name detections (the number of “1” in the bit pattern). Therefore, for example, when the number of matches is “3” and the total number of detected pitch names is “3”, the match rate is “1 (100%)”. If the number of matches is “0” or the total number of detected pitch names is “0”, the match rate is “0 (0%)”, which is regarded as a non-code (a chord is not established).

  Next, in step SD5, it is determined whether or not the coincidence rate calculated in step SD4 is larger than the value of the register Per. In the first pass, since the register Per is reset to zero, the determination result is “YES”, the process proceeds to step SD6, the match rate is stored in the register Per, and the value of the pointer k is stored in the register kbuf. In step SD7, the pointer k is incremented. Subsequently, in step SD8, whether the incremented pointer k has exceeded the number of codes registered in the code type determination table CTDT (total number of code types ChordType), that is, calculation of the coincidence rate for all code types has been completed. Determine whether or not.

  If the match rate has not been calculated for all code types, the determination result in step SD8 is “NO”, and the process returns to step SD4 to calculate the match rate. If the calculated match rate is greater than the match rate stored in the register Per, the determination result in step SD5 is “YES”, the process proceeds to step SD6, and the newly calculated match rate is updated and registered in the register Per. A pointer k designating the updated code rate ChordType of the matching rate is stored in the register kbuf.

Thereafter, steps SD4 to SD8 are repeated until the match rate is calculated for all code types, whereby the highest match rate is stored in the register Per, and the pointer k designating the code type ChordType having the highest match rate is stored in the register. It will be stored in kbuf.
When the match rate is calculated for all code types and the code determination is completed for the code determination section designated by the pointer i, the determination result in step SD8 is “YES”, and the flow proceeds to step SD9. In step SD9, the value of the register kbuf is stored in the determination code Chord [i].

  Next, in step SD10, the pointer i is incremented, and in the subsequent step SD11, it is determined whether or not the code determination section designated by the incremented pointer i has exceeded the end END. If the end END is not exceeded, the determination result is “NO”, and the process returns to step SD2. Thereafter, steps SD2 to SD11 described above are repeated until the code determination section designated by the pointer i exceeds the end END. When the code determination section exceeds the end END, the determination result in step SD11 is “YES”, and this process is completed.

As described above, in the present embodiment, a sound having a shorter sound length than the predetermined sound length is excluded from the sounds constituting the music data MD, and the sound name is detected for each code determination section for the other sounds. Since the determination is made, it is possible to perform accurate code determination without including the elapsed sound or the decoration sound as a code determination target.
Further, in the present embodiment, even if a passage sound or a decoration sound is shorter than a predetermined sound length and there is a sound that is pronounced simultaneously with the sound, the pitch name of each sound that is simultaneously pronounced is detected. Since the chord is determined, it is possible to detect a chord having a short sound length such as a staccato.

  In the above-described embodiment, the sound having a shorter sound length than the predetermined sound length is uniquely excluded from the chord determination target. However, the present invention is not limited to this, and a sound whose velocity (volume) is a predetermined value or less is chorded. Sounds intended by the user, such as excluding them from the judgment target, or including them in the chord judgment target if the velocity (volume) is equal to or higher than a predetermined value even if the sound is shorter than the predetermined length. It does not matter as a mode in which the code is individually determined or excluded. In this case, it is possible to obtain a chord-sounding chord desired by the user, although the accuracy of the chord determination is lacking.

  In the present embodiment, a fixed sound length is determined as a criterion for determining whether or not to include the chord determination target. However, the present invention is not limited to this. For example, when the chord determination section is in units of bars, the eighth note length is set. The following sounds are excluded from the chord determination target, and when the chord determination section is in beat units, the sound of the 16th note length or less is excluded from the chord determination target, etc. It is also possible to make them different. In this way, sounds unnecessary for chord determination can be excluded according to the set chord determination section, thereby making it possible to perform accurate chord determination.

It is a block diagram which shows the structure of one Embodiment by this invention. It is a figure which shows the structure of the code type determination table CTDT. It is a figure which shows the structure of music data MD. It is a figure which shows the structure of the pitch class table PCT. It is a flowchart which shows operation | movement of a main routine. It is a flowchart which shows the operation | movement of a pitch class extraction process. It is a flowchart which shows the operation | movement of a chord process. It is a flowchart which shows operation | movement of a code | cord | chord determination process.

Explanation of symbols

1 CPU
2 ROM
3 RAM
4 Operation section 5 Display section 6 MIDI interface 7 Electronic musical instrument

Claims (6)

Storage means for storing each sound constituting the song;
Chord determination means that excludes a sound having a shorter sound length than a predetermined sound length from each sound stored in the storage means, and performs code determination for each code determination section based on the other sounds. A code determination device. If the sound read from the storage means is shorter than a predetermined sound length, the chord determination means searches the storage means for other sounds that are pronounced simultaneously with the read sound, and if the corresponding sound exists, The chord determination apparatus according to claim 1, wherein the chord determination is performed without excluding a sound having a shorter pitch than the predetermined pitch. Storage means for storing each sound constituting the song;
A setting means for setting a specific sound length corresponding to the set chord determination section and setting the chord determination section;
For each chord determination section set by the setting means based on other sounds, excluding sounds having a shorter sound length than the specific sound length set by the setting means from among the sounds stored in the storage means And a code determining means for determining a code. Chord judgment that memorizes each sound that composes a song, excludes sounds that are shorter than a predetermined tone length from each of the memorized sounds, and performs chord judgment for each chord judgment section based on other sounds A code determination processing program for causing a computer to execute processing. If the sound read from each of the stored sounds is shorter than the predetermined sound length, the chord determination process searches for the other sounds that are pronounced simultaneously with the read sound from the stored sounds, and corresponds. 5. The chord determination processing program according to claim 4, wherein if there is a sound, the chord determination is performed without excluding a sound having a shorter sound length than the predetermined sound length. A storage process for storing each sound constituting the song;
A setting process for setting a chord determination section and setting a specific sound length corresponding to the set chord determination section;
Codes set in the setting process based on other sounds are excluded from the sounds stored in the storing process, excluding sounds having a shorter sound length than the specific sound length set in the setting process A code determination processing program for causing a computer to execute code determination processing for determining a code for each determination section.

Images