Some songs probably started one way, some the other. "Will no one tell me what she sings?", Wordsworth wondered of the Gaelic air he heard "yon solitary Highland lass" who was "single in the field" singing at her work. No, sorry, William. Can't say. ~ But I could have told him what she wasn't singing: "The Barley Mow" ~ tho her father might well have been in the village pub the night before. Surely both strands would have coexisted right from the first, with different songs for different purposes and different occasions.