[i]Terry Pratchett's 'Lords and Ladies' incorporates a lot of plot from Tam Lin and A Midsummer Night's Dream, with three witches and the Lancre Morris Men (signature tune 'Mrs. Widgery's Lodger') thrown in for good measure.[/i]

Tons of references to 70's folk-rock as well, especially Steeleye (Thomas the Rhymer) and Fairport (Tam Lin, natch).