In the ontology of music the Aristotelian theory of musical works is the view that musical works are immanent universals. The Aristotelian theory (hereafter Musical Aristotelianism) is an attractive and serviceable hypothesis. However, it is overlooked as a genuine competitor to the more well-known theories of Musical Platonism and nominalism. Worse still, there is no detailed account in the literature of the nature of the universals that the Aristotelian identifies musical works with. In this paper, I argue that the best version of Musical Aristotelianism identifies musical works with structural universals. I first motivate the view by outlining its explanatory benefits. I then argue that Musical Aristotelianism is preferable to Musical Platonism and present a novel account of musical works as structural universals by developing D.M. Armstrong's theory of structural universals. I discuss the consequences of Musical Aristotelianism with respect to on-going issues in debates about musical works and defend the view against an influential objection, concluding that Musical Aristotelianism is a genuine competitor in debates about the nature of musical works. a work of music is a token of some type. The main disagreement among Musical Platonists concerns the nature of types -whether musical works are eternal types (Dodd 2000) or creatable indicated types (Howell 2002;Trivedi 2002;Walters 2013). Let us call the former view extreme Musical Platonism and the latter moderate Musical Platonism.Musical Platonism has a broader meaning than this type-theoretic interpretation. A Musical Platonist could identify musical works with a Platonic entity that is not a type. They might say a musical work is a Platonic universal. On this Platonic variant, musical works are not types. The relevant contrast, then, between Musical Platonism and Musical Aristotelianism is that musical works, according to the Platonist, are transcendental in the sense that an entity lacks spatial location, is eternal, acausal, or immutable, etc, whereas the Aristotelian says that musical works are immanent. 3 The Musical nominalist provides an account of musical works without positing Platonic types or universals (whether transcendental or immanent). Traditionally, Musical nominalism was understood as the view that musical works are classes of performances (in the same way the nominalist more generally says a property is a class of individuals). More recently, Musical nominalism has taken on a more materialist flavour, without any reference to classes. Ben Caplan and Carl Matheson (2004) have suggested that musical works are mereological fusions of performances and (perhaps) the score, score-copies, recordings, and the compositional activity of the composer; they have styled this theory as a form of perdurantism (Caplan & Matheson 2006). 4 Chris Tillman (2011) has argued that musical works are multiply locatable concrete objects such that a musical work is wholly located at its manifestations; the work coincides with its manifestations. The relevant cont...