From their press release:
SACRAMENTO, CA — January 1, 2008—TheTrackShack.com today launched a brand new marketplace for musicians and fans to buy & sell CDs, Songs, and Tracks. Featuring the first ever CD mastered to offer production-level tracks, Bumped Up To First Class, the new site allows musicians to upload songs, including individual tracks, mix minus ones, videos, lyrics, and sheet music.
Why didn’t I think of that? 
Actually, there seems to be much more to it than just that, including a section for studios to list themselves and their services, artists to do the same, etc. Very much a one-stop-shop. I hope it becomes a viable means to unlock and refactor creativity and commerce in the music industry.
