P.S. It does bear remembering that, as far as I can tell, traditional songs were always viewed by their singers as "old." Not that they wouldn't sing a new song. But they fairly reliably viewed the traditional songs as something tried and true that had originated well in the past, been handed down for a long time -- and they tended to view their own, or their family's, versions as the *correct* versions. "So and so over the mountain sings it too, but she don't sing it right."

So, along with the pastness of traditional songs, there's also a territoriality. "My version versus yours." The songs were at one and the same time everyone's, and personal possessions.

That variability, and that possessiveness, almost by definition cannot happen when a song is obviously manufactured elsewhere, as pop songs are. You may love "Blue Skies" and sing it around the house and your kids may learn it from you and teach it to their kids, but how long will it take before the song's origin is so eradicated that they'll think it's their own?

The traditional is the personal.