No doubt. "Will the Circle Be Unbroken" comes to mind. I think most folks think that AP wrote it, but he didn't. It's just that it's his version we're all so familiar with.

Thank goodness for the AP Carters, Harry Smiths, and Lomaxes of the world. You're right, Ben, without folks like that, lots of those great old songs would have been forgotten

I saw a documentary on Harry Smith the other night. There were some clips of contemporary artists doing their interpretations of songs from the Anthology of American Folk Music. It was awesome. Anyway, something I saw on there is similar to our discussion about PD on Ourstage. Elvis Costello wasn't satisfied with the ending of "Ommie Wise," so he wrote his own. I thought it was pretty cool

http://www.cmt.com/videos/elvis-costello/134160/ommie-wise.jhtml

The McGarrigle Sisters do the original version first, then EC does his.

Enjoy
Eric