A music information calculation apparatus recognizing a structure of a piece of music based on an acoustic signal. The apparatus includes: an acoustic signal input for inputting the acoustic signal of the piece of music; an acoustic parameter calculator for calculating, using the acoustic signal, at least a first acoustic parameter indicating a volume of the piece of music; an inflection degree calculator for calculating, using at least the first acoustic parameter, an inflection degree indicating an inflection of the piece of music; a story node calculator for calculating, using at least the first acoustic parameter, a story node representing a time at which a formation of the piece of music changes; and a story information calculator for calculating, as story information indicating at least a correspondence between the story node having been calculated and the inflection degree obtained at the time represented by the story node.