| 摘要 |
PROBLEM TO BE SOLVED: To enhance chord detection accuracy by automatically dividing playing information to the plural parts meeting the playing information and executing the chord detection in accordance with these plural parts. SOLUTION: The key chord of the key touch tones of a keyboard 4 is stored. Interrupt processing is executed at every one piece of the eight notes in a CPU 1 by the interrupt signal from a timer 10. The key chord generated in the keyboard 4 are analyzed to four parts; a base voice part, a base chord voice part, melody chord voice part and melody voice part. Single voice part analysis, two voice part analysis, three voice part analysis and >=4 voice part analysis are carried out according to the number of touched keys. The parts of the touched key tones are determined by the combinations of plural conditions, such as the pitch of tones, whether timing is a bar top or not, whether downbeat tone or upbeat tone, the interval from the previous base voice part tone and the interval with the previous melody chord voice part tone. If the chord cannot be detected in the part of the chord voice part, the chord is detected in accordance with the parts of the chord voice part and the melody voice part. |
