Coffitivity works well for me, it's not music, it's ambient noise http://www.coffitivity.com/
[edit] I just read on their page that their theory is "It's pretty hard to be creative in a quiet space". So while I like the "hotel lobbby" feel for some kinds of work, I disagree that silence is bad.
OTOH, this might work for me because I can't parse engilsh that well.