See this earlier discussion: John Barleycorn, which contains rather a lot of links to additional material. I put them there in the (evidently forlorn) hope that people might actually use them.

"Traffic" recorded a fairly straight arrangement of the song as they learned it from The Penguin Book of English Folk Songs. I do recall hearing, long ago, a set of the song fitted to the Victorian hymn-tune (evidently from The Songwainers), but it wasn't traditional.