Well, both my girls had their own versions of songs. Fer instance; Molly was convinced that "there was a bathroom on the right" and Hillary wanted someone (?) to "Stop in the neighborhood" While these don't qualify as folk music they illustrate problems common to thos of us who use old recordings or their "re-masters" for our sources. When I am learning from a live "folk" and I'm confused, I ask what was just sung until I'm sure I know what words were used. I also use writen sources for words but ya gotta be careful for there were (are) some anthologists who change songwords for arcane (and probably nefarious) reasons.
Boy would I like to learn the "real" words to Wildwood Flower! Where's at?