The Mystic Knights of the Oingo Boingo were a musical theater troupe started by Danny Elfman's older brother Richard Elfman. Richard left the troupe and Danny decided to form a Rock band. Oingo Boingo was born from many of the same musicians including Steve Bartek, Leon Schneiderman, Dale Turner, and Sam 'Sluggo' Phipps. Danny eventually left the band to compose the theme for The Simpsons, the score for The Nightmare Before Christmas (for which he also sang the Jack Skellington role), and pretty much every other movie done by Tim Burton, and plenty more. Steve Bartek still works with Danny on his musical scores.