A legacy is something inherited by a successor, and in Boulez’s case what he handed down to posterity (his writings, activities and compositions) evolved in complex ways from his own early mentors and influences, particularly Messiaen, along with what the young Boulez determined to be the essential innovations in works that had the greatest unfulfilled potential in the 1940s and early 1950s. Boulez’s own works were naturally part of his legacy but in his later years changes in musical fashion meant that his accomplishments as conductor, writer, teacher of performers and institutional figurehead provided an even more potent example to potential emulators than his actual compositions. His unambiguously modernist sensibility and concern to place serious music at the heart of the prevailing culture brought a remarkable coherence to bear on the rich diversity of his life and work.

This chapter presents an understanding of compositional practice based fundamentally on sound and space, and looks at a range of case studies that explore the harmonic, timbral, and material consequences of this approach. The chapter concludes by arguing that the variety of approaches discussed succeed because the concern with sound permeates every stage of compositional thinking and does not just manifest in specific compositional techniques.

The spectralist composers in Messiaen’s class of 1971#–2 are an important part of Messiaen’s legacy. This chapter addresses how Messiaen’s work was essential to the creative thinking of Tristan Murail and Gérard Grisey. It focusses on what these composers absorbed from Messiaen and how they qualified, extended, and enriched his legacy. In particular it understands these composers through the lens of an ecology of listening in which the concerns of the listener are an active formant in the compositional thinking.