Patent ID: 8442816

Claim:
A music-piece classifying apparatus comprising: a processor; first means including a frequency analyzer implemented by the processor for converting audio data related to at least a portion of a music piece into data components in respective different frequency bands for every unit time interval to generate time frequency data pieces assigned to the respective different frequency bands; an effectiveness detector implemented by the processor for detecting, for each of the frequency bands, a data component satisfying a prescribed condition as an effective component for every unit time interval; second means including a sustain region detector implemented by the processor for analyzing said time frequency data pieces generated by the first means and thereby deciding, for each of the frequency bands, whether or not at least a first prescribed number of effective components detected by the effectiveness detector are present in a reference time interval equal to said unit time interval multiplied by a second prescribed number, and detecting a sustain region corresponding to said frequency band in cases where it is decided that at least the first prescribed number of effective components detected by the effectiveness detector are present in said reference time interval; third means including a feature quantity calculator implemented by the processor for calculating a feature quantity from at least one of (1) a number of the sustain regions detected by the second means and (2) magnitudes of values calculated from the data components in the sustain regions; and fourth means including a classifier device implemented by the processor for classifying the music piece in response to the feature quantity calculated by the third means.