I don't use music when playing.
When I tried to do that, I found several problems between each players, so no music when I'm the GM. No time wasted looking for the track that - maybe - fits in the scene.
Maybe I will try to use music again, only for the background, but I will not care to change it during the game, just one long track. If you can describe the situations and the feeling of, and if your players are "in" the game, they will feel the pain, fear, happiness... whatever you want.
Maybe, for background music for OTE free jazz is a good option (event not thinking about the game the next link is a must) youtube.com/watch?v=YedVpRzF900
Or maybe music from Cage (another "must") youtube.com/watch?v=BowyUXyNud4
But think in heavy metal... I should say that I don't like it...