Writing with Music

I was wondering about music and writing. Some writers need total silence, others need constant background noise. And of course some of us are in between. I like working in quiet or with very soft music in the background that's relevant to what I'm writing--whether it's the mood of the piece or if it happens to be the kind of music my main character would listen to.

I find that music can help me with voice. If I listen to music my character would listen to, it makes it a lot easier to understand that character's reaction to the scene. It's kind of fun.

What about you?