When Olivier Messiaen (1902-1992) completed the vast opera Saint Francois d'Assise in 1983, he was mentally and physically exhausted, and believed that this monumental work would be his final compositional statement. Seven further works emerged, however, and these form the focus of the present study. Christopher Dingle suggests that, following the crisis provoked by the opera, Messiaen's music underwent a discernable change in style. He examines these seven works to identify characteristics of the composer's music, in particular an often overlooked aspect of his technique: harmony.Part I of the book begins with a brief historical survey before discussing Saint Francois d'Assise as the work which defines everything that follows. Part II examines the series of miniatures that came after the opera and their links with his final masterpiece, Eclairs sur l'au-dela. The latter work forms the subject of Part III of the book. Each movement is analysed in turn, before the work is considered as a whole and its hidden structure and motivic cohesion is revealed.