I get it, GUEST, Someone Else (sorry Richard, I get there eventually). OK, coming off soapbox, don thinking cap on...

Actually, there IS a word to describe what you want. Don't laugh when you read it, but it means "having been passed along from generation to generation". It is tralatitious. An example of its use: "Among Biblical critics a tralatitious interpretation is one received by expositor from expositor".

So, your category 1 above then becomes "tralatitional", and category 2 "tralatitional attributable". The remainder is just "folk".

OK, who will be the fist to start a Tralatitional Music Club?