OK so we have character themes being discussed. But what about tunes we love (some secretly because they're so impossibly cheesy) that would fit so well in things like battle scenes or dramatic invocations of elder horrors?
Eschewing classical music (that's low hanging fruit- what battle scene wouldn't go great with the crescendo of Liszt's Led Preludes? or Sauron forbid "Ride of the Valkyries"?), what tunes would you play and for what bits?
I'm going to peg myself as 80s rocker chick but so what? Here's some great battle music
Black Sabbath: Neon Knights (which should seriously be the official theme song of Dungeons and Dragons as a game) -
This I think is Bass' theme music:
I've been known to put on the Battlesate Galactica (new series) soundtrack when I'm playing, as I find the style of music is very... adventurous, I guess.