System & Contrast : a Polymorphous Model of the Inner Organization of Structural Segments within Music Pieces (Original Extensive Version)

At a large timescale, music pieces can be described as the succession of structural segments which form the global organization of the piece. The present article proposes a model called "System & Contrast", which aims at describing the inner organization of such structural segments in terms of : (i) a carrier system, i.e. a sequence of morphological elements forming a matrix network of self-deducible syntagmatic relationships and (ii) a contrast, i.e. a substitutive element, usually the last one, which partly departs from the logic of the system. The S&C model applies at several timescales and to a wide variety of musical dimensions in a very polymorphous way, therefore offering an efficient meta-description of mid-level musical content.