Duplicate tracks - what to do?

This is just a random idea, probably useless. Say I've got 4 instances of a track, say one from the original album, one from a Now! compilation, one from a friend's mix tape and one from a fiim soundtrack, if I listen to them all, the play count for that song in the 'bird is misrepresented as it's shared 4 ways. But, if I delete 3 of the duplicates, when I want to listen to the albums which should contain the track, 3 of them no longer will.

So would it be possible to add support for having a single instance of the track (and thus a better representation of the play count) and for it to 'belong' to multiple albums? would that mess with last.fm? I don't know if anything like that would work but it's an age old problem. Are there any decent solutions?