I typically find The Weavers; Burl Ives &c in the “Oldies” section, if there is one. Which definition takes precedence walking in, yours or the shopkeeper's? Genre labels are for inventory. They 'exclude' everthing they don't 'include':

One Harry Belafonte album was titled Calypso.
The Billboard chart was “Popular.”
The Grammy was “Folk.”
The current used media/boot sale bin is “Pop/Male Vocal” moving toward “Oldies” & it's still just the one & same album it's always been.

Personal definitons aren't of much value even to the person having them. Most folks will just use alpha-by-artist at home.