When did the period of musical Romanticism end? This question is enticingly simple, but the answer is surprisingly difficult. Drawing on the recent developments in the historiography of late nineteenth- and early twentieth-century music, this chapter examines some of the categories commonly used to describe this period – late Romanticism, early modernism, maximalism, and Weltanschauungsmusik – and their methodological and epistemological orientations. It will be argued that these categories, far from being merely convenient labels for stylistic categorisation, can be understood as different responses to the complex historiographical challenges arising from the destabilised ontological foundation of the work-concept. Grounded in a discussion of the alienation between Arnold Schoenberg and Richard Strauss between 1909 and 1914, this chapter contends that the question concerning the end(s) of musical Romanticism can thus only be rendered approachable as a heuristic idea, in the way it prompts us constantly to question, challenge, and rethink the historiographical foundations of an era.