Since analytic aesthetics began, around 50 years ago, music has perhaps been the art most discussed by philosophers. The reasons for philosophers' attraction to music as a subject are obscure, but one element is surely that music, as a non-linguistic, non-pictorial, multiple-instance, performance art, raises at least as many questions about expression, ontology, interpretation and value as any other art—questions that often seem more puzzling than those raised by other arts.