It is faulty to use the same criteria for "traditional" in today's world as for centuries past. The literacy rate was lower, printed sources of music were scarce, musical notation was not on printed sources, etc., etc., etc. Music was passed by oral tradition because there was no other possiblity.

Nowadays we have printed music and copyrighted music and a greater number of people are literate. Most musicians know how to read music and most are aware of copyright laws. Hence modern tunes will probably not tend to develop variations at the rate earlier tunes did.

In the same manner I think it is faulty to say that a tune is not traditional/folk if there is a known author. Is Ye Roast Beef of Old England less traditional because we know Leveridge wrote it? Is it less of a folk tune? Surely many songs we consider traditional started out as formal publications.

But, of course, I am not an academic and I'm far less of a folk scholar than most. And so I won't offer my own definition - I think it's a pretty subjective term!

Martin Neff has an interesting page on "what is folk" here (http://www.coe.ufl.edu/courses/EdTech/Vault/Folk/Definition.htm).