"Travellers come as near to one as dammit" Yes, I think your accounts of people who lived a partially pre-literate (and pre-portable TV) life could be something of a window on the past. Especially your quote (I think it was you), in another discussion, about someone getting the family songs printed to sell at the fair.

However, I was also thinking of people in earlier times doing what many did before one could just download lyrics - writing it down (for the ring binder...) from an oral source, learning it, singing it and then later someone else writing it down and the cycle repeats.

I know of one song collected from an oral source in the 1950's where, unbeknown to the collector, the family of the singer have a few handwritten versions, with assorted misshearings and corrections, going back over four or five generations. A child learns to write, takes down granny's song, sings it herself and then her daughter writes it down after hearing it. Is that oral transmission?