Absolutely. I find that I have a much easier time jumping back into a particular character's mindset and figuring out their motivations if I've set up a playlist for them. Mind you, I'm a music junkie and have always used tunes to help me focus, so it's not all that surprising that I tend to go this route.

Hmm...lessee, I wrote a character over on Pre named Jacobi Harris, a power hungry politician with a knack for speechifying. Found this little gem, which suit him perfectly. The best part, despite being song that explained him better than I ever could have, I didn't find it until I'd been writing him for a few months.