The Diary of Mr. Gray, conceived as a rock play set in the 1920's, revolves around a
psychiatrist who is reading the diary of Mr. Gray, presumably his patient. Mr. Gray had
gone mad as a result of drug use. Through the diary, we see the world through the eyes.of a madman. The album covered 50 years of the recording industry, including a 78 rpm, a stereo recording, and a quadraphonic recording. The album is now a cult classic.