Is it real, a cosmic coincidence, an ingenious marketing ploy, or just another conspiracy theory? What are the chances that one of the most beloved movies of all time is artistically linked to one of the greatest rock albums ever recorded? For the uninitiated, the "Dark Side of the Rainbow" theory asserts that Pink Floyd purposely synchronized The Dark Side of the Moon to The Wizard of Oz. For those who have seen it, the mashup produces dozens of striking coincidences between the film and the album, where actions on the screen seemingly correspond to the lyrics, chords and musical moods of the Dark Side tracks. In addition to a complete viewing guide for the synchronicities, the book explores an explanation for their existence.