A lot of topics introduced here.
Lyrics sung to other tunes: Woody Guthrie hardly ever created an original tune; he made new lyrics to old songs he remembered. For that matter, Emily Dickinson's poems are mostly written to the meter of hymns she heard in church. Some wicked juxtapositions occurred that way. To update it somewhat, try singing "Because I Could Not Stop For Death" to the tune of "I'd Like to Teach the World to Sing"

Folk process: To me, the folk process, if it hasn't died quite entirely, was profoundly changed in the course of the last century with the burgeoning and widespread dissemination of recordings. Many songs "in flux" were forever fixed by recordings made by such as Peter Paul and Mary, the Kingston Trio, the Weavers, and The Beach Boys. You can hardly deviate in performance from those canonical arrangements without people thinking you must have screwed up. It's like what photography did to representational painting. The one category in which the folk process is strong is in funny songs played by local bands. People sort of half-remember the lyrics and because they are tickled by a song's concept, they'll write new lyrics incorporating as much as they remember. Look at the various versions of "The Folksinger" (sung to the tune of "The Boxer") that are floating around on the web. This song was written by someone, yet the proliferation of versions has overwhelmed the original. A key aspect of this is that the song, if recorded at all, was not widely distributed.

Dylan's betrayal of folk: Look at "Positively Fourth Street" by David Hajdu for the way the Newport audience actually reacted to Bob Dylan's electric performance. There wasn't a vast walkout of folk traditionalists, and the critical reception wasn't outfaged either.

There, I've rambled on more than anyone here. Beat me up.

Regards,
Steve