If we look at the form a Folk Song is most likely to take then that's going to be as much about its morphology as it is about its derivation. And what about the Derivation of those Forms? Which is an important thing to consider with respect of the Traditional Idiom, be it the Traditional (Anon) songs themselves, those found in Broadsides, or the vernacular writings of Tommy Armstrong and the psuedo-folk of Rudyard Kipling from the Barrack-room Ballads to the Puck Songs etc.