In analyses of music and film interaction, the interpretative approach to film music has usually been given through the picture and music/sound relation. It has been considered predominantly through the prism of mimetic theories that take the act of visualization for their model. Such a simplification is mirrored in the classic distinction of source music and background music. We can note that the term source music refers solely to its representing function, not the narrative one. A turn in defining film music also in relation to narration and not only and specifically in relation to picture, was the merit of Claudia Gorbman, an American theorist. In her study Unheard melodies she re-systematizes the interpretative practice introducing the theory of narration into it. By using one of the key terms in film theory, diegesis, she constructed the terms diegetic and non-diegetic music, which refer to the sound/music scene: the first one would, approximately be equivalent to source music, and the second one to background score. Diegetic music is seen through the dialectic structure made of two planes, the narrative (film story) and narration (the process through which the narrative is conveyed to the viewer/listener), and whose constituents are music and picture, i.e. their fluctuating relation. Non-diegetic music is the one whose source is beyond the frame both explicitly and implicitly, but it has a meaningful relation to the film story. This text considers the ways in which music, diegetic or non-diegetic, participates in narration, i.e. performs not only the representative function but the narrative one as well, within a complex structure of a film system, based on examples from national and world cinematography.