Beastie Boys in a movie caleed Tougher than Leather back in 1988 with Run DMC?

Question

The Beastie Boys were rhymin a rap on stage with what sounded like the opening song from the movie, The Good the Bad, and the Ugly playing in the background.It had a cool beat to go along with their rap.I never found this song on any of thei earlier albums.Any one have a clue what this song is called and where to get it ?

Answer 1

if I recall the song was: Desperado