The score for the movie was composed by the incarcerated killer Bobby Beausoleil, one of the infamous Charles Manson family killers. He was in jail when he made the score.
The film's score was composed by Kenneth Anger's original choice to play Lucifer, Bobby Beausoleil who was in prison at the time, serving a life sentence for his involvement with the Manson murders. It is the only film score to be written and recorded wholly in a prison.
Originally Kenneth Anger wanted Jimmy Page to score the film but he didn't care for the music when Page finally delivered. This is one reason why the film took so long to be made.
The special effects are courtesy of Wally Veevers who also worked on Stanley Kubrick's seminal 2001: A Space Odyssey (1968).
Lucifer was originally played by Chris Jagger, but squabbling between him and Kenneth Anger led to Jagger returning to London and Anger taking over the role.