Abstract: A music piece development analyzer includes: a comparison target sound detector configured to detect a sound production position of a comparison target sound in a form of a sound of a predetermined musical instrument from music piece data; a sound production pattern comparing unit configured to set at least two comparison sections each having a predetermined length in the music piece data, compare the at least two comparison sections in terms of a sound production pattern of the comparison target sound, and detect a similarity degree of the sound production pattern between the at least two comparison sections, and a development change-point determining unit configured to determine a development change-point of the music piece data based on the similarity degree.