Well that depends...me and my girlfriend had music in the background once before, we were watching the sunset at the beach in my car, and i had some "soft" hip hop in the background. "cant leave em alone" by ciara and 50 cent, and a few other songs. It made our foreplay really...well for lack of a better word special. All we did was foreplay but still...

You should try it with a movie playing in the background, that usually is what happens with us, because we both love movies, and both love making out and foreplay so its only natural that it would go hand in hand lol :D

I dont, too distracting imho..

Love music since I listen to it all the time at home; seems normal during sex as long as it's not blasting. I listen to an eclectic mix; therefore, much depends on the mood. Sometimes rock, alternative, and older stuff...

I lost my virginity to North African trip hop and Arabic ambient lounge music. Music always turns me on or seems to make sex fun, not that it is not fun without though.
Some hardcore industrial or metal can bring out your inner beast, dance can make you feel more energetic, chillout tunes can be good too. It all depends on how music normally makes you feel and if you think it would add to the overall experience.
The sound of your breathing and moaning against the backdrop of silence or a busy city stree below can be just as good ;)

My gf and I watched underworld one time and when it was over, things started to happen. The main menu screen music was great for having sex apparently. Clawing at each other and so on. Vampire sex basically! It was great!

Beethoven's Moonlight Sonata
Rufus Wainwright's Evil Angel

Wagner's Ride of the Valkyries? (Does anyone remember a movie called The Long Swift Sword of Siegfried?)