It would be very interesting if the users themselves could change the album's tracklist. To have a control and avoid errors could be implemented a voting system, similar to the covers. Its much more practical and the site would be more up-to-date. Lately many albums are with the wrong tracklist
Personally I think it would be best to use (somewhat) reliable sources like Last.fm tries to do (even it it has a few bugs to work out) rather than letting anyone change a track listing. Just think about what trolls would be doing with that.