Next to nothing, except there were one or two decent songbooks with a few traditional melodies that aware teachers would use.

My early folk schooling came from home. Mum's Scottish heritage, Dad's English heritage, their church-folk influence, camp songs, boy scout and girl guide songs, all combined with the requisite music theory.

I dare say that if my piano studies had included some folk music I would have stuck with it longer, but Conservatory books in the '60s and '70s were pretty much all "classical" (that is to say classical, baroque, romantic...).

As for other folk culture, nada.

Peace, Mooh.