I'm not sure or not, correct me if I'm wrong, but when MTM was being finished they had 17 tracks and then decided to cut 5? I can't reamber if this was stated somewhere or not.
No Roads Left, 6th String Song are only two that come to mind. Unless you count QWERTY stuido version (But I don't think this song was ever intended for the final cut).
So really, it could be the 6th string song or something we never knew was out there?
My guess is though that it is the 6th string song just cause Mike knows everyone knows about it and has been asking about it.
Can't wait till December!
Edit: Also, I hope Mike gives us some decent info next week about the new LP.