Patent ID: 7179981

Claim:
A music structure detection apparatus detecting a structure of a music piece in accordance with chord progression music data representing chronological changes in chords in the music piece, comprising: a partial music data producing device which produces partial music data pieces each including a predetermined number of consecutive chord transitions starting from a position of each chord transition in said chord progression music data; a comparator which compares each of said partial music data pieces with said chord progression music data from each of the starting chord positions in said chord progression music data, on the basis of an amount of change in a root of a chord in each chord transition and an attribute indicating a type of chord after the chord transition, thereby calculating degrees of similarity for each of said partial music data pieces; a chord position detector which detects a position of a chord transition in said chord progression music data where at least one indicating higher similarity of the similarity degrees calculated for each of said partial music data pieces is obtained; and an output device which calculates a number of times that the calculated similarity degree indicates the higher similarity for all said partial music data pieces for each chord transition position in said chord progression music data, thereby producing a detection output representing the structure of the music piece in accordance with the calculated number of times for each chord transition position.