Sorry Lighter - didn't want to confuse issues in one big posting.
Nothing you put up provides an alternative definition, though it does raise a number of important points, particularly about literacy.
That songs are orally composed and transmitted in no way implies an i;;iterate population - far from it.
The fact that literacy has played a major part in the transmission of folk songs is now becoming more recognised, but exactly what part that has been has yet to be fully understood.
All the other points you raise refer to definitions of folk song, lore, vernacular, etc., as being the culture of society as a whole, not a self-interested section of a dwindling number of folk clubs - it is the former that changes the language and our understanding of it, not the latter.
And your consensually agreed alternative definition is......?
"If you like a song, go ahead and sing the bloody thing!!."
Don't thing anybody disagrees with this Don - no need to shout
Jim Carroll