In this paper I defend a contextualist interpretation of authenticity in musical performance: we judge a performance as authentic not in respect of a stable set of requirements but according to contextually determined factors. This solution is the natural outcome of an independently supported ontological account of musical works: Musical Stage Theory. The aim of the paper is to give new momentum to the debate concerning the notion of authenticity and to challenge a monistic interpretation of authenticity: there is not (...) one authenticity but many. (shrink)