Well folk music is either a time capsule heading deeper into history with each passing year, or a living tradition which its proponents claim? If it's alive and sets store by its own definitions, I presume someone can give evidence for the transmission which is so important to its claims of vitality?

IMO the important thing is the singers. If they lay claim to a tune, if they adopt it, it IS folk. What other definition of a living tradition can there be?