So, considering the enormous number of verses used to tell the story, I decided to make a multi-column layout and turn it into a PDF, so that it would be easy to print, read, and carry.
I give you: Ballad of Tam Lin (PDF).
It's based on the sheet music and verses collected at Digital Tradition. To listen to a computer version of the tune, go directly to the song on digital traditions and hit the play button. I have a suspicion though that the traditional song was played a bit faster than the computer rendering of it, with all those verses!