JP4230324B2 - Code detection device for electronic musical instrument, code detection method and program - Google Patents

Description

  The present invention relates to a chord detection technique for an electronic musical instrument, and more particularly to a technique for detecting a base route.

  Some electronic musical instruments include an automatic accompaniment device that detects chords by inputting from a keyboard and converts an automatic accompaniment pattern incorporated along the detected chords to perform.

  Some chord detection methods can select a mode in which a certain chord is determined from the time when one key is pressed, a mode in which a chord is determined when the key is pressed, and the like.

  Further, when a fraction code detection switch is provided and the fraction code can be detected, there is one that detects based on the lowest key of the depressed key. The fraction code is, for example, “C / B”, the numerator code is the code of the upper part (code part) of the score, and the denominator code is the code of the lower part (base part) of the score.

  In the mode in which the code is determined from 3 keys, only the denominator of the code (hereinafter referred to as the base route) is changed when the key is pressed with 2 keys or less, and the base route can be freely specified with the numerator code fixed. There is.

  First, as shown in FIG. 2A, a case where the base route (baseline) is sequentially lowered will be described. When the key “Domiso” is pressed at time t1 to t2, the code “C / C” is detected. Next, when one key “do” is pressed at times t3 to t4, “C / C” is detected. Next, when one key “Sh” is pressed at times t5 to t6, “C / B” is detected. Next, when one key “L” is pressed at time t7 to t8, “C / A” is detected.

  Next, a case where the base route sequentially rises as shown in FIG. When the key “Domiso” is pressed at time t1 to t2, the code “C / C” is detected. Next, when one key “so” is pressed at times t3 to t4, “C / G” is detected. Next, when one key “L” is pressed at time t5 to t6, “C / A” is detected. Next, when one key “Sh” is pressed at time t7 to t8, “C / B” is detected.

  Next, as shown in FIG. 2C, a case where the bass route is lowered by the legato playing method will be described. At time t1 to t2, three keys “Domiso” are pressed, at time t3 to t5 “do” is pressed, from time t4 to t7 “shi” is pressed, and at time t6 to t8 “la”. A case where the key is pressed will be described. At time t1, since “Domiso” of the three keys is pressed, the code “C / C” is detected. Next, at time t3, since one key “do” is pressed, the code “C / C” is detected. Next, at time t4, since the two keys “Sid” are pressed, the code “C / B” is detected using the lowest key “S” as the base route. Next, at time t6, since the two keys “Lashi” are pressed, the code “C / A” is detected using the lowest key “L” as the base route. In this case, an appropriate code can be detected as in the case of FIG.

  Next, as shown in FIG. 2D, a case where the bass route is raised by the legato playing method will be described. In this case, a problem occurs in code detection. At time t1 to t2, three keys “Domiso” are pressed, at time t3 to t5 “so” is pressed, from time t4 to t7 “L” is pressed, and at time t6 to t8 “sh” is pressed. A case where the key is pressed will be described. At time t1, since “Domiso” of the three keys is pressed, the code “C / C” is detected. Next, at time t3, since one key “So” is pressed, the code “C / G” is detected. Next, at time t4, since the two keys “Sora” are pressed, an inappropriate code “C / G” is detected using the lowest key “Sora” as a base route. However, at time t4, since “La” is newly depressed, the code “C / A” should be detected. Next, at time t6, since the two keys “Lashi” are pressed, the code “C / A” is detected using the lowest key “L” as the base route. However, at time t6, the key “C” is newly pressed, so the code “C / B” should be detected. As described above, in the case of FIG. 2D, an inappropriate code is detected unlike the case of FIG. 2B.

  Further, in Patent Document 1 below, the lowest note is obtained from key press information when three or more keys on the keyboard are pressed, and each pitch name corresponding to the pressed key is determined based on the lowest note. Determining the pitch is disclosed.

  Further, in Patent Document 2 below, when a large number of keys are pressed simultaneously, the lowest tone in the pressed keys is set as a root tone, and one chord is selected from standard chords. It is disclosed that key data that constitutes is formed.

JP-A-10-55181 JP-A-6-130957

  An object of the present invention is to provide a chord detection technique for an electronic musical instrument that can perform appropriate chord detection when a bass line is played with a legato playing method.

According to one aspect of the present invention, when there are three or more key pressing states at the same time, a fractional code including a base route can be detected based on the pitch of the three or more key pressing states, based Once the code has been detected by the first code detecting means and said first code detecting means for detecting the pitch name of the lowest tone of the pitch of the depressed state of the three or more keys as the base root When a line legato is played, if two keys are pressed at the same time, the pitch of the last sounding start instruction is detected as the bass route, and if one key is pressed, the pitch is detected. There is provided a chord detection apparatus for an electronic musical instrument having a second chord detection means for detecting only a base route among fractional chords detected by the first chord detection means as a base route.
According to another aspect of the present invention, when there are three or more key pressed states at the same time, a fractional code including a base route can be detected based on the pitches of the three or more key pressed states. A first chord detection step of detecting a pitch name of the lowest note of the pitches of the three or more key pressed states as a base route, and after a chord is detected by the first chord detection step When two bass keys are pressed at the same time during the bass line legato performance, the pitch of the last sounding start instruction is detected as the bass root, and when one key is pressed, the pitch is detected. Is detected as a base route, and a chord detection method for an electronic musical instrument is provided that includes a second chord detection step for changing only the base route among fractional chords detected by the first chord detection step.
According to still another aspect of the present invention, when there are three or more key pressed states at the same time, a fractional code including a base route can be detected based on the pitches of the three or more key pressed states. A first chord detection step for detecting a pitch name of the lowest note among the pitches of the three or more key pressed states as a base route, and after a chord is detected by the first chord detection step When playing the legato of a bass line, if there are two keys pressed at the same time, the pitch of the last sounding start instruction is detected as the bass route, and if there is one key pressed, the sound A program for detecting a height as a base route and causing a computer to execute a second code detection step of changing only the base route among fractional codes detected by the first code detection step. Beam is provided.

Even when the playing baseline legato rendition style can detect the appropriate code.

  FIG. 1 shows a configuration example of a chord detection apparatus for an electronic musical instrument according to an embodiment of the present invention. The keyboard 101 includes a plurality of keys for performing a performance operation. When the key is pressed, key-on (including pitch) is generated, and when the key is released, key-off (including pitch) is generated. Instead of the keyboard 101, other performance operators may be used. The code detection unit 103 includes a code detection unit 104 with three or more keys and a code detection unit 105 with two or less keys, and performs code detection according to the key depression of the keyboard 101. By pressing the fraction code detection switch, the code detection means 103 can detect the fraction code.

  When there are three or more key-on inputs from the keyboard 101 at the same time, the three-or-more-code detection means 104 can detect a fractional code (including a base route) based on the pitch of the three or more key-ons. . At that time, the three or more key code detecting means 104 detects the lowest note name of the three or more key-ons as a base route. The numerator of the fraction code is represented by the code route and the code type, and the denominator of the fraction code is represented by the base route. For example, when “Doremi” is pressed, the chord “C / C” is detected with the chord root “C”, the chord type “major”, and the base route “C” with the lowest sound.

  The code detection means 105 for two keys or less detects the fractional code by the code detection means 104 for three keys or more, and if there are two or less key-ons simultaneously, the last (latest) key-on note name is used as the base route. Detect and change only the base route among the fraction codes.

  The style number selection unit 102 selects an automatic accompaniment style such as rock or jazz, for example, according to a user operation, and outputs the style number.

  The automatic accompaniment means 106 reads out an automatic accompaniment pattern corresponding to the style number and performs automatic accompaniment according to the fractional code detected by the chord detection means 103. Automatic accompaniment is performed, for example, by repeatedly generating a predetermined pattern of a chord part and / or a bass part. The chord part is pronounced according to the chord root and chord type, and the base part is pronounced according to the base root.

  First, as shown in FIG. 2A, a case where the base route (baseline) is sequentially lowered will be described. When the key “Domiso” is pressed at time t1 to t2, the code “C / C” is detected. Next, when one key “do” is pressed at times t3 to t4, “C / C” is detected. Next, when one key “Sh” is pressed at times t5 to t6, “C / B” is detected. Next, when one key “L” is pressed at time t7 to t8, “C / A” is detected.

  Next, a case where the base route sequentially rises as shown in FIG. When the key “Domiso” is pressed at time t1 to t2, the code “C / C” is detected. Next, when one key “so” is pressed at times t3 to t4, “C / G” is detected. Next, when one key “L” is pressed at time t5 to t6, “C / A” is detected. Next, when one key “Sh” is pressed at time t7 to t8, “C / B” is detected.

  Next, as shown in FIG. 2C, a case where the bass route is lowered by the legato playing method will be described. At time t1 to t2, three keys “Domiso” are pressed, at time t3 to t5 “do” is pressed, from time t4 to t7 “shi” is pressed, and at time t6 to t8 “la”. A case where the key is pressed will be described. At time t1, since “Domiso” of the three keys is pressed, the code “C / C” is detected. Next, at time t3, since one key “do” is pressed, the code “C / C” is detected. Next, at time t4, since “Sid” of two keys is depressed, “C” of the last (last) key of them is used as a base route, and the code “C / B” is detected. Next, at time t6, since the two keys “Lashi” are pressed, the code “C / A” is detected with “L” as the last key among them as the base route. In this case, an appropriate code can be detected as in the case of FIG.

  Next, as shown in FIG. 2D, a case where the bass route is raised by the legato playing method will be described. In this case, if the lowest key of two or fewer keys is detected as the base route, an inappropriate code is detected as described above. As in the present embodiment, an appropriate code can be detected by detecting the two-key or less code detection means 105 as the base route of the key presses of two or less keys.

  At time t1 to t2, three keys “Domiso” are pressed, at time t3 to t5 “so” is pressed, from time t4 to t7 “L” is pressed, and at time t6 to t8 “sh” is pressed. A case where the key is pressed will be described. At time t1, since “Domiso” of the three keys is pressed, the code “C / C” is detected. Next, at time t3, since one key “So” is pressed, the code “C / G” is detected. Next, at time t4, since the two keys “Sora” are pressed, an appropriate code “C / A” is detected using the last key “S” as the base route. Next, at time t6, since the two keys “Lashi” are pressed, an appropriate code “C / B” is detected using the last key “Shi” as a base route. As described above, in the case of FIG. 2D, an appropriate code can be detected as in the case of FIG.

  FIG. 3 is a block diagram illustrating a hardware configuration example of the electronic musical instrument according to the present embodiment. A sound source (TG) 302, a CPU 303, a panel 304, a keyboard 305, a ROM 306, a RAM 307, a D / A converter 308, and a MIDI interface 311 are connected to the bus 301.

  The CPU 303 performs various calculations or processes, and executes the processes shown in FIGS. 4 to 7 and the like described later according to the computer program stored in the ROM 306. The timer 312 supplies time information to the CPU 303. The CPU 303 can perform a timer process of FIG. 6 described later according to the time information. The ROM 306 stores automatic accompaniment data and the like in addition to the computer program. The RAM 307 is used as a working area for the CPU 303. The panel 304 includes a switch and a display device (for example, a liquid crystal display), and has a style number selection switch, a fraction code detection switch, and the like.

  The keyboard 305 has a plurality of keys that can be pressed and released. When the keyboard 305 is depressed, a key-on event including a velocity (key-pressing speed) and a key number (pitch) is transmitted to the CPU 303, and when the keyboard 305 is released, a key-off event is transmitted to the CPU 303. When a key is pressed in the key detection key area of the keyboard 101, a code is detected based on the key pressed. The CPU 303 reads the automatic accompaniment data in the ROM 306 based on the selected style number, converts the automatic accompaniment data of a predetermined pattern based on the detected chord, and repeats sound generation processing. The MIDI interface 311 can input and output performance data and the like as MIDI data to the outside.

  The sound source 302 generates a musical tone signal based on performance data or automatic accompaniment data obtained by operating the keyboard 305. The D / A converter 308 converts the digital musical tone signal generated by the sound source 302 into an analog format and outputs it to the amplifier 309. The amplifier 309 amplifies the musical sound signal, and the musical sound is generated by the speaker 310.

  The CPU 303 repeatedly performs the keyboard process in FIG. 4 and the chord detection process in FIG. 7 in the main routine, and interrupts the timer process in FIG. 6 at predetermined time intervals.

  FIG. 4 is a flowchart showing a keyboard process performed when a keyboard operation is performed. In step S401, a code detection map creation process is performed. Details of this processing will be described later with reference to FIG. Next, in step S402, a sound generation process or a mute process according to the keyboard operation is performed. That is, a sound generation process is performed when a key-on occurs due to a key depression of the keyboard, and a mute process is performed when a key-off occurs due to a key release from the keyboard. Next, in step S403, if the recording switch is pressed, recording processing of performance data or the like based on keyboard operation is performed. Next, in step S404, a MIDI transmission process is performed in response to a MIDI (musical instrument digital interface) transmission instruction. That is, MIDI data corresponding to the operation of the keyboard is transmitted to the outside via the MIDI interface 311. Next, in step S405, other processing is performed. Thereafter, the keyboard process is terminated.

  FIG. 5 is a flowchart showing details of the code detection map creation processing in step S401 of FIG. First, in step S501, it is checked whether the key event generated by the keyboard operation is key-on or key-off. If the key is on, the process proceeds to step S511, and if the key is off, the process proceeds to step S502.

  In step S511, a predetermined time is set in the ON detection request counter. The on-detection request counter has a predetermined time when a player presses a chord composed of multiple key constituent sounds with a slight time lag, so the chord can be detected immediately after the key is pressed. It is the time required to detect the code after waiting for a predetermined time. The on-detection request counter is decremented by a timer process in FIG.

  In step S512, the generated key-on pitch is set in the chord detection key map. The chord detection key map has a flag corresponding to the pitch of the number of keys of the keyboard 305, and only the key-on pitch flag is set.

  Next, in step S513, it is checked whether the fraction code detection switch is on or off. If it is on, the process proceeds to step S514, and if it is off, the process proceeds to step S518. In step S518, since the fraction code is not detected, the base key (base route) is set to OFF, and the process proceeds to step S519.

  In step S514, in order to detect the fraction code, it is checked whether or not the number of keys pressed is two or less. If the key pressed is 2 keys or less, the process proceeds to step S515, and if it is 3 keys or more, the process proceeds to step S516.

  In step S516, it is checked based on the chord detection key map whether or not the pitch of the lowest key-on key has changed compared to the previous time. If there is a change, the process proceeds to step S517, and if there is no change, the process proceeds to step S519.

  Step S517 is processing when the number of keys pressed is three or more, and the base key (base route) is set to the pitch of the lowest key during key-on. Thereafter, the process proceeds to step S519. Step S515 is processing when the number of key presses is two or less, and the base key (base route) is set to the pitch of the final (last) key during key-on. Thereafter, the process proceeds to step S519.

  In step S519, the base detection request flag is set, and the code detection map creation process ends. By setting the base detection request flag, it is determined that the code detection process is performed in step S703 in FIG.

  In step S502, the pitch flag key-offed this time in the chord detection key map is cleared. Next, in step S503, it is checked whether key-on due to the current key depression remains based on the code detection key map. If the key-on remains, the process proceeds to step S504, and if it does not remain, the process proceeds to step S505.

  In step S504, a predetermined time is set in the off detection request counter. The off-detection request counter will release the constituent sound with a slight time lag when the performer releases the chord consisting of the constituent sounds of multiple keys. Instead, this is the time required to detect a new code after waiting for a predetermined time. The off detection request counter is decremented by a timer process in FIG. Thereafter, the process proceeds to step S505.

  In step S505, it is checked whether the fraction code detection switch is on or off. If it is on, the process proceeds to step S506, and if it is off, the code detection map creation process ends.

  In step S506, it is checked whether or not there is a change in the pitch of the lowest key-on key compared to the previous time, based on the code detection key map. If there is a change, the process proceeds to step S507, and if there is no change, the process proceeds to step S508.

  In step S507, the bass key (bass route) is set to the pitch of the lowest key during key-on. Thereafter, the process proceeds to step S510.

  In step S508, it is checked whether all keys are key-off. If all keys are key-off, the process proceeds to step S509, and if not, the code detection map creating process is terminated. In step S509, the base key (base route) is set to OFF, and the process proceeds to step S510.

  In step S510, the base detection request flag is set, and the code detection map creation process ends. By setting the base detection request flag, it is determined that the code detection process is performed in step S703 in FIG.

  FIG. 6 is a flowchart showing the timer process. In step S601, it is checked whether the ON detection request counter is counting. Specifically, if the on detection request counter is not 0, it is determined that counting is in progress. If it is counting, it will progress to step S602, and if it is not counting, it will progress to step S605.

  In step S602, the ON detection request counter is decremented. Next, in step S603, it is checked whether or not the count of the on detection request counter is completed. If the count ends, the process proceeds to step S604, and if not complete, the process proceeds to step S605. In step S604, an ON detection request flag is set. By setting the ON detection request flag, it is determined that the code detection process is performed in step S701 in FIG. Thereafter, the process proceeds to step S605.

  In step S605, it is checked whether the off detection request counter is counting. Specifically, if the off detection request counter is not 0, it is determined that counting is in progress. If it is counting, it will progress to step S606, and if it is not counting, a timer process will be complete | finished.

  In step S606, the off detection request counter is decremented. Next, in step S607, it is checked whether the count of the off detection request counter has ended. If the count is finished, the process proceeds to step S608, and if not finished, the timer process is finished. In step S608, an off detection request flag is set. By setting the off detection request flag, it is determined that the code detection process is performed in step S702 of FIG. Thereafter, the timer process is terminated.

  FIG. 7 is a flowchart showing the code detection process. First, in step S701, it is checked whether an on detection request flag is set. If it is set, the process proceeds to step S704, and if it is not set, the process proceeds to step S702. In step S702, it is checked whether an off detection request flag is set. If it is set, the process proceeds to step S704. If it is not set, the process proceeds to step S703. In step S703, it is checked whether or not the base detection request flag is set. If it is set, the process proceeds to step S704. If it is not set, the code detection process is terminated.

  In step S704, an octave key map is created based on the code detection key map. The octave key map has a pitch name flag of one octave (12 keys), and the pitch on the chord detection key map is converted to a pitch name of one octave.

  Next, in step S705, the code is determined with reference to the code detection table. That is, the chord root and chord type are determined based on the key-on component sound on the octave key map. The chord detection table is a table showing the relationship between constituent sounds and chords. If there is no constituent sound in the chord detection table, the chord is indeterminate. For example, when the number of constituent sounds is 2 or less, the chord is indeterminate.

  Next, in step S706, it is checked whether the code is confirmed. If the code is confirmed, the process proceeds to step S707, and if not confirmed, the process proceeds to step S720. In step S707, code update processing is performed. Specifically, in step S707, the confirmed code is compared with the previous code, and in step S708, it is checked whether or not the current code has been updated. If updated, the process proceeds to step S709, and if not updated, the process proceeds to step S720.

  In step S709, it is checked whether or not the off detection request flag is set. If it is set, the process proceeds to step S711. If it is not set, the process proceeds to step S710.

  In step S710, information with retrigger and the confirmed code are recorded. At this time, if the base route is set, the fraction code including the base route is recorded, and if the base route is set as off, the base route is not recorded. The retrigger process is performed in steps S718 and S719 described later. Thereafter, the process proceeds to step S712.

  In step S711, as in step S710, information without retrigger and the confirmed code are recorded. Thereafter, the process proceeds to step S712.

  In step S712, the determined code is displayed on the liquid crystal display (LCD). Next, in step S713, it is checked whether or not the automatic accompaniment mode is set by the user's switch operation. If it is the automatic accompaniment mode, the process proceeds to step S714; otherwise, the process proceeds to step S725.

  In step S714, it is checked whether an off detection request flag is set. If it is set, the process proceeds to step S715. If it is not set, the process proceeds to step S717.

  In step S717, it is checked whether or not the base route has been changed. If the base route has been changed, the process proceeds to step S718, and if not changed, the process proceeds to step S719. In step S718, base part retrigger request processing is performed. That is, the bass part that is currently automatically accompanied is muted, and the pace part is automatically accompanied according to the new bass route. Thereafter, the process proceeds to step S719. In step S719, code part retrigger request processing is performed. That is, the chord part that is currently automatically accompanied is muted, and the chord part is automatically accompanied according to the new chord root and chord type. Thereafter, the process proceeds to step S725.

  In step S715, the pitch of the bass part currently being automatically accompanied is changed by the vendor process, and then the pace part is automatically accompanied according to the new bass route. Next, in step S716, the chord part is automatically accompanied by muting sound other than the key-on component from the chord part currently being automatically accompanied. That is, the automatic accompaniment of the chord part is continued so as to mute the sound with the key-off. Thereafter, the process proceeds to step S725.

  In step S720, it is checked whether the base detection request flag is set. If it is set, the process proceeds to step S721, and if it is not set, the process proceeds to step S725.

  In step S721, information with retrigger and code (for example, base route) are recorded. Next, in step S722, a code is displayed on the liquid crystal display. Next, in step S723, it is checked whether or not the automatic accompaniment mode is set by the user's switch operation. If it is the automatic accompaniment mode, the process proceeds to step S724, and if not, the process proceeds to step S725.

  In step S724, base part retrigger request processing is performed. That is, the bass part that is currently automatically accompanied is muted, and the pace part is automatically accompanied according to the new bass route. Thereafter, the process proceeds to step S725.

  In step S725, the ON detection request flag is cleared. Next, in step S726, the off detection request flag is cleared. Next, in step S727, the base detection request flag is cleared. This completes the code detection process.

  As described above, after detecting a chord based on the pitch of three or more key-ons, if there are two or less key-ons at the same time, the last key-on of them is detected as a base route. As shown in (D) and (D), an appropriate chord can be detected even when a bass line is played with a legato performance.

  This embodiment can be realized by executing a program by the computer of the electronic musical instrument of FIG. Also, means for supplying a program to a computer, for example, a computer-readable recording medium such as a CD-ROM recording such a program, or a transmission medium such as the Internet for transmitting such a program is also applied as an embodiment of the present invention. Can do. A computer program product such as a computer-readable recording medium in which the above program is recorded can also be applied as an embodiment of the present invention. The above program, recording medium, transmission medium, and computer program product are included in the scope of the present invention. As the recording medium, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  The above-described embodiments are merely examples of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed as being limited thereto. That is, the present invention can be implemented in various forms without departing from the technical idea or the main features thereof.

It is a figure which shows the structural example of the code | cord | chord detection apparatus of the electronic musical instrument by embodiment of this invention. FIGS. 2A to 2D are diagrams for explaining a code detection method corresponding to a key depression. It is a block diagram which shows the hardware structural example of the electronic musical instrument by this embodiment. It is a flowchart which shows the keyboard process performed when there exists keyboard operation. It is a flowchart which shows the detail of a code | cord | chord detection map preparation process. It is a flowchart which shows a timer process. It is a flowchart which shows a code | cord | chord detection process.

Explanation of symbols

101 Keyboard 102 Style number selection means 103 Code detection means 104 Three or more keys code detection means 105 Two keys or less code detection means 106 Automatic accompaniment means 301 Bus 302 Sound source 303 CPU
304 Panel 305 Keyboard 306 ROM
307 RAM
308 D / A converter 309 Amplifier 310 Speaker 311 MIDI interface 312 Timer

Claims (6)

If there are three or more key pressed states at the same time, a fraction code including a base route can be detected based on the pitch of the three or more key pressed states, and the three or more key pressed states are detected. First chord detection means for detecting a pitch name of the lowest note of the pitches of
When a bass legato is played after the chord is detected by the first chord detector, if the two keys are pressed at the same time, the pitch of the last sounding start instruction is detected as the bass root. And second chord detection means for detecting the pitch as a base route when one key is pressed, and changing only the base route among fractional codes detected by the first chord detection means; A code detection device for an electronic musical instrument. Furthermore, it has a keyboard that includes a plurality of keys and generates a key-on when a key is pressed.
2. The chord detection apparatus for an electronic musical instrument according to claim 1, wherein the first and second chord detection means perform detection according to a key depression of the keyboard.   3. The electronic apparatus according to claim 1, further comprising automatic accompaniment means for performing automatic accompaniment according to a chord detected by the first chord detection means and / or a bass route detected by the second chord detection means. Instrument chord detection device.   4. The chord detection apparatus for an electronic musical instrument according to claim 3, wherein the automatic accompaniment means performs automatic accompaniment of a chord part and / or a bass part. If there are three or more key pressed states at the same time, a fraction code including a base route can be detected based on the pitch of the three or more key pressed states, and the three or more key pressed states are detected. A first chord detection step of detecting a pitch name of the lowest note of the pitches of
When a bass legato is played after the chord is detected in the first chord detection step, if there are two keys pressed at the same time, the pitch of the last sounding start instruction is detected as a bass root. A second chord detection step of detecting the pitch as a base route when one key is pressed, and changing only the base route of the fractional chords detected by the first chord detection step; A method for detecting a chord of an electronic musical instrument. If there are three or more key pressed states at the same time, a fraction code including a base route can be detected based on the pitch of the three or more key pressed states, and the three or more key pressed states are detected. A first chord detection step of detecting a pitch name of the lowest note of the pitches of
When a bass legato is played after the chord is detected in the first chord detection step, if there are two keys pressed at the same time, the pitch of the last sounding start instruction is detected as a bass root. A second chord detection step of detecting the pitch as a base route when one key is pressed, and changing only the base route of the fractional chords detected by the first chord detection step; A program that causes a computer to execute.

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