One of the pioneers of musique concrete and electronic tape manipulation, 'Prelude Au Sommeil' is Perrey's debut recording but shows a composer already at maturity. Originally released at the end of the fifties, as a private press under the fake institutional name "Institut Dormiphone", it consisted of 2 side-long tracks played on the Ondioline (a vacuum-tube based, spring-loaded electronic instrument). The music contained in this mysterious vinyl is like something between dreamy church organ hymns and the keyboard-based minimalism that Philip Glass and Terry Riley developed a decade later. It was intended as sleep-inducing and tranquilizing for use in mental hospitals. It is unclear if the copies pressed actually had been distributed to mental hospitals or if the whole story was just a fantastical joke on the part of Mr. Perrey. Essential. Limited to 500 copies.