Mr Carroll - I really must differ from you (although rather nervously) regarding your last post.
If there were a way folk song should sound, it would have been mentioned already in this thread.
Does it matter who wrote "You'll never walk alone"? it will eventually be out of copyright anyway. And do those who sing along on a Saturday afternoon think about that? (it'd be interesting to know if royalties have been demanded!)
Is the oral tradition not maintained by repeating what has been heard. Modification/evolution comes with time (or mishearing).
"Happy Birthday" has been passed on from parent to child, and between children, almost ever since it was written. And it is sung because folks WANT to sing it. That surely is folk. God save the queen has not; most peope don't want to sing it - even musicians hate it - and I totally agree it is not folk! (I've never tried leading off with it in a session though - nor am I likely to!)
All folk is not far better. Folk inhabits a broad spectrum, just like everything in life, and there's always room for 'the stone that the builder rejected' Some of the not so good bits may indeed be rather ephemeral though.
I think I get less and less sure about how I would define folk music, indeed folk arts generally. And while musicians, artists and academics may be the guardians of the tradition, surely it has to be relevant to "ordinary" folk, or it has no meaning.
And my respect for the work you do, and the people who have been your "sources". Strange though that you don't mention musicians - but then most musicians have to have a day job.
Tony