Olivier-Eugène-Prosper-Charles Messiaen (French: [ɔlivje mɛsjɑ̃]; December 10, 1908 – April 27, 1992) was a French composer, organist, and ornithologist, one of the major composers of the 20th century. His music is rhythmically complex; harmonically and melodically it often uses modes of limited transposition, which he abstracted from his early compositions and improvisations. Messiaen also drew on his Roman Catholic faith for his pieces.