In this paper, I examine notions of musical gesture and their possible compositional and analytical applications. As a point of departure, I provide a provisional definition of musical gesture; I then posit a theory of gesture classification that draws on language used in post-tonal set theory, in order to develop the formalized structures of gesture-classes and gesture-class sets. These concepts serve as the basis for my analysis of music by Franco Donatoni, Cecil Taylor, and Mari Kimura. I use Franco Donatoni’s Omar: due pezzi per vibrafono to present and illustrate how a set theory of gesture can be applied to musical composition. Building on the sets shown in Omar, I discuss Cecil Taylor’s Indent in order to demonstrate systems of gestural flow between gesture-classes and gesture-class sets. Finally, I use Mari Kimura’s Clone Barcarolle to exemplify the complex relationships that exist in the hybrid space between musical and physical gestures. Through each of these brief case studies, I aim to provide vocabulary with which to describe music that can be seen as gestural in conception or construction, as well as insight into possibilities for new forms of composition based on exploration of gesture as a formal musical element.