Abstract: Three conditions are necessary for a performance of a work and together are sufficient: (1) the performance matches the work's content, more or less; (2) the performers intend to follow most of the instructions specifying the work, whoever wrote them; and (3) a robust causal chain runs from the performance to the work's creation. Live performances are individuated not solely in terms of the spatio-temporal unity of the playing event, but also with respect to the performing group involved. Studio performances, by contrast, are identified with the simulated or virtual performances encoded on a master, or its clones.

Keywords: follow, live, match, performance, studio, work,