The tune in folk music is always changing. Jazz players have done their versions
of popular tunes and renamed them. I don't see a problem here. I don't agree that
Dylan's versions are superior to the originals. I have no problem with someone taking an idea or story and changing it to suit a different time or his/her personality.

Art is thievery. If I put new lyrics to Nottamun Town or the Patriot Game and Dylan's lawyers attempted to sue me, then I would have a problem with that attempt.

The folk process runs counter to music copyright laws in this country controlled by the licensing agencies such as ASCAP, BMI and SESAC.

I think as Jean Ritchie says that it's good form to acknowledge the source for one's song if it is a tune. I also know that sometimes a song can be rewritten to improve it. Folk songs are rewritten (called variants) to reflect the time of the person doing the rewriting.

A.P. Carter rewrote songs to fit in with the Carter Family concerts.   Ie: "I Will Twine Midst The Ringlets of My Raven Black Hair" composed by English ladies, became "Wildwood Flower", a traditional staple.

Folk singers do this, and so what? "Solidarity Forever", an important contemporary statement about unionism based on the "Battle Hymn of the Republic" is being sung today in the halls of Wisconsin State House. Everything here is a matter of context.

Pete Seeger, Woody Guthrie, Dylan and others use trad tunes for new ideas.
I do it myself. The copyright laws are at fault here. They need to be revamped to include the folk process.