Kendall, you raise a most provocative issue, perhaps suited for a thread all its own: At what point does folk, a literary or musical work unattributable to any identified creator(s), become traditional? 60 years? 59? 40?
For instance, to choose something in questionable taste, take the song about Hitler having only big ball, to the tune of "The Col. Bogey March," which had to have been written in the 1940s. Unless we know its authorship, I'd call it folklore.
Are songs of unknown origin from World War II old enough now to be considered traditional? At some point that song was new: folklore but not traditional.
How do we define traditional? Anything that existed before the age of recording whose authorship is unknown?