Mark Sparling has posted 70 music and ambient sound tracks for use in game projects.
You can preview the lot on Soundcloud.
Mark has posted a playlist of the tracks he thinks are the best on his website here: http://marksparling.com/free-music-2/
At the time of this writing you can still download all 70 tracks via this mediafire link.
mp3 versions of the tracks are available via a separate download.
Note from the creator: “I’m licensing all of these under Creative Commons Attribution, so you can use them for any games commercial or not. If you decide to use any of my music, please credit me and included a link to my website: http://marksparling.com/ and/or Soundcloud and/or twitter (@Markymark665)”