Can't see the word 'borrowed' in there Jim, what it does do is talk about a 'form' and that dreadful word 'style' two words that could, in the context of the paragraph be interchangeable.

What it actually says is that there are new songs in that 'form' or 'style', and here they are as part of the definition of 'Folk Music'

Precisely what I've been saying, and you've been denying all along!