This was a good thread & I'm glad it got resurrected. While it's here, two adds--

Believe it or don't, "Gospel Hymns Old and New" contains "How Can I Keep from Singing?" set to the tune of "America" (Oh, Beautiful, for Spacious Skies). It ALMOST works; you have to fudge the last note of each line. That also means that America and Barbree Allen are interchangeable.

Also, Cumberland Gap and Shortnin' Bread, for those tradists who were not killed by Dylan. Sorry, couldn't resist. I plan to combine those two as countermelodies rendered on the 'courtship dulcimer.' That's just before I acquire a life. :)

CC