I see where listening to music can aid some people's writing. The expression of emotion through song is powerful, allowing you to transfer those emotions into your prose. Sometimes. If you're good at it. Unfortunately, my writing suffers when I'm exposed to too much emotion. I learned that the ideas I typically get while watching movies are best left as an outline until I've let the ideas simmer for at least a night. That, coupled with the noise, is why I don't tend to write while listening to music?
How about you? Music?