I dug this out for the talk next week
It explains how the old crowd differentiated between the different types of their song
It's from the time Appalachian singer Jean Richie was recording songs from singers in Ireland in 1950 - a definition using recognition and comparison

“I used the song Barbara Allen as a collecting tool because everybody knew it.
When I would ask people to sing me some of their old songs they would sometimes sing ‘Does Your Mother Come from Ireland?’ or something about shamrocks.
But if I asked if they knew Barbara Allen, immediately they knew exactly what kind of song I was talking about and they would bring out beautiful old things that matched mine, and were variants of the songs I knew in Kentucky. It was like coming home.”
Jim