F oolestroupe: I think you're a bit wrong there, I dont think you've thought about all the ways traditions can be transmitted. Consider the local school where you live. That is where the locaL accent is being passed on, and not just the accent: the style of talking, of walking, of facial expressions, alll sorts of stuff. It doesnt matter if the parents and child have just arrived in the district from 200 miles away, or if the child was born there. They will acquire the same local style. And this is not affected by what the child gets from the parents, as long as the child is fairly young.. They get stuff from their peers, or from those a year or two older.
   I live in Stoke(England). I know a young Rumanian refugee, with a thick Stoke accent. He learnt that in the playground, he didnt come to England till he was 8 (as far as I remember).
   It can be the same with musical traditions. I didnt learn how to play hornpipes from my dad, but I did learn "from the tradition" as they say. It just so happened my dad didnt play hornpipes, though he did play the church organ. And my mum played the flute. But I learnt tunes from other people. Or books,sure, but you dont learn style from books. Style you learn from the air you breathe.