Originally planned as part of a three picture deal between Carol White and National General (the first of which was Daddy's Gone A-Hunting (1969)); she eventually was replaced by Jacqueline Bisset. Working title was "Angel."
Writer and producer Garry Marshall's sister Penny Marshall (pre-Laverne & Shirley (1976)) plays one of the band's groupies, The Plaster Casters, in the orange T-shirts. The name is an homage to Cynthia Plaster Caster, whose crew of groupies created plaster casts of famous rock star genitalia. In fact, in the first shot of Penny admiring the band from the audience, she plays suggestively with a tape measure.
Richard Morgan's airplane is a Rockwell 500 Aero Commander.