Today we have an old Scottish ballad of the ‘fantastical’ variety. ‘Mainly Norfolk’ tells us ‘This is a truly magical ballad. It was first mentioned in The Complaynt of Scotland in 1549 but no words were published until Herd put a fragment into his Ancient and Modern Scots Songs in 1769. It never seems to have been collected outside Scotland’. It is sung for us here by the great Sandy Denny and Fairport Convention, from their album Liege and Lief, which first appeared in 1968.
Mainly Norfolk has an excellent page on Tam Lin here; it includes a copy of the lyrics as Sandy Denny sings them in this recording, along with several other versions. Fairport Convention have left out quite a few of the verses to make the song shorter; some of the other versions give a fuller account. For more information than you can possibly imagine, check out Abigail Acland’s comprehensive Tam Lin pages here. Alternatively, if you want the Coles Notes version, Wikipedia will do quite nicely!
Fairport Convention are surely one of the most influential folk-rock bands of all time; this Wikipedia article tells their story, and their official website is here. More information about the late Sandy Denny can be found at her official website here; Wikipedia is also quite helpful.