In his review of Martin Scorsese’s 2013 film The Wolf of Wall Street, Variety’s Scott Foundas suggests that having ‘a quadruple album’s worth of classic rock and blues fill up the soundtrack’ contributes to the film being ‘almost self-consciously Scorsesean’ in its style. Yet even a cursory survey of the music heard both in that film and across Scorsese’s oeuvre reveals an eclecticism not accounted for by this view. This chapter argues instead that pre-existing music, and the director’s particular manners of employing it, are common and thus defining features of his work, forming a key part of his authorial signature, and indeed doing so more strongly for him than for perhaps any other mainstream filmmaker.