This thesis explores the role that film genre plays in the construction of, predominantly, Hollywood movie scores. It begins with the simple assumption that each genre has its own set of musical conventions, its signature “paradigm”, with the result that Westerns sound different from Horror films, which sound different from Romantic Melodramas and so on. It demonstrates that while this is broadly speaking so, the true picture is more complex, the essentially hybrid nature of most Hollywood films on a narrative level resulting in scores that are similarly hybrid in nature. To begin with, the various functions of film music are described, and that of generic location is isolated as being of key importance. The concept of film genre is then discussed, with particular reference to the notion of hybridity. The substance and sources of the musical paradigms of the Western, Horror film and Romantic Melodrama are described in depth; specific aspects of the War Film, Gangster, Thriller and Action paradigms are addressed more briefly. The thesis concludes with a cue by cue analysis of John Barry’s score for Dances with Wolves (1990), demonstrating that while the dominant paradigm the music draws on is indeed that of the Western, the score also incorporates elements from a variety of other generic paradigms, shifts in musical emphasis that are dictated by the changing requirements of the narrative. Film music is shown to be profoundly influenced by film genre, but that the use of generically specific music is as complex and nuanced as cinema’s negotiation of genre at narrative level. While genres do indeed have signature musical paradigms, these do not exist discretely, but in constant tension with and relation to one another.