In 1971, he was asked to compose a piece for the Paris Opéra. While reluctant to undertake such a major project, he was persuaded in 1975 to accept the commission and began work on his "Saint-François d'Assise". The composition was intensive (he also wrote his own libretto) and occupied him from 1975 to 1979; the orchestration was carried out from 1979 until 1983. Messiaen preferred to describe the final work as a "spectacle" rather than an opera. It was first performed in 1983. Some commentators at the time thought that the opera would be his valediction (at times Messiaen himself believed so), but he continued to compose. In 1984 he published a major collection of organ pieces, "Livre du Saint Sacrement"; other works include birdsong pieces for solo piano, and works for piano with orchestra.