Abstract: Musical works can be for live performance, for studio performance, or for playback, not performance. The ‘thinner’ the work, the less the work determines details of its accurate instances, but even the ‘thickest’ of works for performance leave their performers with considerable scope for interpretation. These ways of describing musical works, unlike ones considering them as classes, types, or kinds, provide an ontology reflecting factors that are significant to the way composers, performers, and listeners understand and discharge their socio-musical roles.

Keywords: live, ontology, performance, playback, studio, work,