The gestation period of György Kurtág's Hommage à R. Sch. op. 15d covers a period of approximately fifteen years (1975-1990). Using sketches and drafts conserved in the Kurtág Collection of the Paul Sacher Foundation, this paper seeks to examine how compositional style and technique change over time and how these changes effected the composer's work concept. Over the past thirty years, sketch studies have opened up new avenues of research, promising wider knowledge of compositional processes and providing insights into the genesis of specific works. Nonetheless, they also render problematic our ability to circumscribe work identity. Rather than focusing on the finite nature of the completed composition as it appears in the published score, the study of sketch material sets the work in a compositional process, revealing not only sources but also half-realised possibilities and unrealised potential. For all the problems it brings to the study of music, such an approach seems particularly apt for a better understanding of Hommage à R. Sch., which appears to emerge out of a network of both complementary and contradictory tendencies.