The Midnight Special was a late-night rock music series airing Friday nights (or rather early morning Saturdays). This 90-minute show followed "The Tonight Show starring Johnny Carson." 
In its first years, The Midnight Special began at 1:00 am. But when Johnny Carson cut his own show from 90 to 60 minutes, Midnight Special's starting time was changed to 12:30am. NBC broadcast the pilot on August 19, 1972 as a 90-minute special. The Midnight Special became a weekly series beginning February 2, 1973.For most of its run, the series featured guest hosts each week. The exception to this was from July 1975 through March 1976 when Helen Reddy was the regular host. Wolfman Jack was a regular fixture on the series. He served as announcer and frequent guest host. Around 1978, at the height of the Disco craze, the studio was changed to resemble a Disco nightclub.