Ok I haven't seen this yet but of course it's featured in Jackie Brown and the music that begins when they show Helmut Berger on TV is what caught my attention, pretty awesome if you ask me. Is that the main theme?
I dunno, I love that theme myself, has a kind of 'boards of canada' feel to it. Most of the music in the film is good too, I'd love to have the soundtrack but obviously its probably never been released and probably never will. Do you own the film on region 1, titled beast with a gun? Worth having.
It's a fantastic song. Occasionally, I will plug in the DVD just to listen to the opening theme. Hopefully cinevox will put something out. I'm surprised no bootlegs are floating around.