| 摘要 |
There is provided a tempo detection apparatus capable of detecting, from the acoustic signal of a human performance of a musical piece having a fluctuating tempo, the average tempo of the entire piece of music and the correct beat positions, and further, the meter of the musical piece and the position of the first beat. The tempo detection apparatus includes an input section 1 for receiving an acoustic signal; a chromatic-note-level detection section for applying an FFT calculation to the received acoustic signal at predetermined time intervals to obtain the level of each chromatic note at each of predetermined timings; a beat detection section 2 for summing up incremental values of respective levels of all the chromatic notes at each of the predetermined timings, to obtain the total of the incremental values of the levels, indicating the degree of change of entire sound at each of the predetermined timings, and for detecting an average beat interval and the position of each beat from the total of the incremental values of the levels; and a measure detection section 3 for calculating the average level of each chromatic note for each beat, for summing up incremental values of respective average levels of all the chromatic note for each beat to obtain a value indicating the degree of change of entire sound at each beat, and for detecting a meter and the position of a measure line from the value indicating the degree of change of entire sound at each beat.
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