An exceedingly rare Beatles collectible—a poster for the Million Volt Light and Sound Rave, an electronic music and light festival held at the Roundhouse in London, on January 28, 1967.(br)Sometimes referred to as the Carnival of Light Rave, the event featured the only playback ever of the legendary 'Carnival of Light,' a fourteen minute sound collage by The Beatles, recorded especially for the event during the sessions for 'Penny Lane' (and advertised on the poster as 'Music Composed For The Occasion by Paul McCartney.')(br)The genesis of the track came in December 1966 from designer David Vaughan, who had recently painted a psychedelic design on a piano owned by Paul McCartney. About the same time as he delivered the piano to McCartney's Cavendish Avenue address, he asked if McCartney would contribute a musical piece for the upcoming event. To Vaughan's surprise McCartney agreed, and drafted all of the Beatles to participate.(br)"Carnival of Light" was only played once, at the Million Volt Light and Sound Rave, and has never been released nor bootlegged. Beatles expert Mark Lewisohn, one of the few who have ever heard the track, says the song included "distorted, hypnotic drum and organ sounds, a distorted lead guitar, the sound of a church organ, various effects (water gargling was one) and, perhaps most intimidating of all, John Lennon and McCartney screaming dementedly and bawling aloud random phrases like 'Are you alright?' and 'Barcelona!'(br)In 1996 McCartney tried to release the track on the compilation album The Beatles Anthology 2, but George Harrison voted to reject it, because according to McCartney "he didn't like avant garde music.'(br)While other bands performed live, including Soft Machine, Tonics, and the New Vaudeville Band, it is the Beatles' 'Carnival of Light' that made the Million Volt Light and Sound Rave a legendary event.(br)The poster measures 20' x 30,' and is in near excellent condition, with some expert restoration. A small piece, approximately ¼' square, is missing from the lower right corner, but could easily be replaced. We know of a few handbills for this event, but this is the only poster we have ever seen (We know of only one other example, illustrated in the British poster book "High Art.")