I love writing to music. I recently received the BODY & SOUL set (stay tuned for the reviews). I listened to one CD already and I must say it will put you in the most romantic mood. The music was able to take my mind to a place where I hadn't been in awhile. The next time I need to write a romantic scene, I know exactly what CD to pop into the CD player.
When I get a momentum going, I either listen to some neo-soul or pop. My mind seems to be more alert and my fingers seem to tap faster while it plays in the background.
Music and writing goes hand in hand. Well in my opinion anyway.
I'm even known to listen to some hip-hop when I'm writing a club or party scene.