Chalk this up to the “probably has been there forever but I just found out about it today” column, but RuneScape’s made a huge amount of its soundtrack available for free. Right here. There are even remixes and shanties. SHANTIES, people! The second best word in the world that ends in “anties”! I wish every MMO studio would do this for their music.
Update: And here’s some for Ryzom that’s also free!
And yes, I’m adding that to the MMO Music page on this here site. As always, if you know of any MMO scores that are either (a) for sale through a digital download somewhere or (b) being given out for free — legally — by the studio, let me know!