Book excerpt: Olivier Messiaen's Oiseaux exotiques is arguably the first of Messiaen's major works to create a successful synthesis between his music and his passion for ornithology. Messiaen regarded birdsong as music--a belief that led for a time to an obsession with truth-to-nature. Here, Peter Hill and Nigel Simeone provide the background to Oiseaux exotiques, discussing Messiaen's relations with the 1950s avant garde and his involvement with the concerts of the Domaine musical, for which Oiseaux exotiques was composed. The authors analyse Messiaen's compositional methods in unprecedented detail and trace step-by-step the evolution of musical ideas from first notation to finished score.