Nice one, Hoot!

At the risk of repeating myself (100s of times) the 54 thing is NOT a definition, it is a list of descriptors to enable scholars to identify what might be folk songs. If one accepts that, then all we have to argue about is the relevance of each descriptor and how it applies to each version of each song. I strongly suspect that all here would be happy to accept those descriptors (excepting the one that was immediately ditched). I'll leave you to guess which one that was.

Steve's Venn diagram is by far the best approach. No music genre, and precious few genres of any kind, is defined by a finite boundary.