We've seen a good number of folk tunes from unexpected sources-
what about great pop-rock covers by folk singers?
I'm thinking of "Rag-Doll" and "Rave On" by Steeleye Span
just now (as they are playing on my "iTunes" player)
Also I'm recalling Mary McCaslin's renditions of "Pinball
Wizard" (on the banjo! incredible!) and "Set Me Free"