Patent ID: 7582824

Claim:
A tempo detection apparatus comprising: input means for receiving an acoustic signal; chromatic-note-level detection means 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; beat detection means 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 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 indicating the degree of change of entire sound at each of the predetermined timings; and measure detection means for calculating the average level of each chromatic note for each beat, for summing up incremental values of the respective average levels of all the chromatic notes 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.