This thesis evaluates Lydia Goehr’s claim that the musical work-concept did not regulate musical practice before the watershed date of 1800. In the first chapter, I evaluate Goehr’s arguments for this claim from historical musicology. I appeal both to recent secondary research sources in musicology, and to philosophical analysis. The second and third chapters focus on philosophical aspects of Goehr’s watershed claim. In the second chapter, I focus on understanding Goehr’s claim that a regulative shift occurred during the watershed date—that (...) is, a change in the norms of musical practice. I argue that this shift is properly understood as a shift in unconscious, rather than conscious, concepts about musical practice. In the third chapter, I consider the ontological implications of Goehr’s view; Goehr adopts a view according to which musical works do not exist. I show that the argument for this view is unsound. (shrink)