I can vouch for the OP. She's a friend of my daughter at Leeds University and is a serious researcher. Please don't discourage a young enthusiast. Suggesting things for her to read and listen to is very vaulable. Apart from that, how is she to get hold of living material that's evolving without speaking to the people who sing and play it?

Thanks for the helpful replies.

Valmai (Lewes)

P.S. Another quite large area of change, I think, is where the supernatural element was removed from British songs travelling to America because it offended religious sensibilities.