The Prélude, usually affixed with the subtitle pour orgue, is an organ piece in E major by French composer Olivier Messiaen. The work, which dates from the 1920s, is, along with the Offrande au Saint Sacrement, the earliest surviving organ work of the composer. Scholars differ as to the exact date and purpose as to when and why it was composed. It is usually known as the Prelude for Organ in English to distinguish it from the Preludes for piano and the posthumously published piece from 1964. The piece along with the Offrande were discovered by Yvonne Loriod in 1997. The Prélude was published posthumously in 2002 by Éditions Alphonse Leduc. It currently remains overlooked and is one of the lesser-known organ works of the composer. History In 1919, Olivier Messiaen entered the Conservatoire de Paris, which was widely considered the most important musical school in the nation. He studied there until 1930. Based on the handwriting style of the manuscript, its location of Paris, style of composition, which reflects in some aspects the music of his organ teacher Marcel Dupré; and organ compass, scholars deduced that the work was composed in the second half of the 1920s. Messiaen had written a supposedly complete catalogue of his works in Technique de mon langage musical (1944). It therefore came as a surprise to Yvonne Loriod, who found the Prélude and Offrande au Saint Sacrement in boxes by the composer's personal desk, to have discovered these pieces in 1997. She sent photocopies of these pieces to colleagues Naji Hakim, who succeeded Messiaen as titular organist of the great organ at Sainte-Trinité Church; and Olivier Latry, one of the titular organists of Notre-Dame de Paris. The piece was revealed publicly for the first time on the CD Inédits and was played by Naji Hakim at the organ of La Sainte-Trinité off a facsimile of the manuscript annotated by Loriod herself. It was published by Editions Alphonse Leduc (AL 29 914) in 2002 following the Offrande's publication the preceding year. The writer of the preface was Olivier Latry. Latry edited the music and Hakim, the registration. Dates In the published short preface to the work, Latry implies that Messiaen wrote it while studying at the Conservatoire de Paris, citing the influences of Dupré, the Diptyque from this time, and importantly, the inclusion of notes that were unavailable within the ranges of most organs available