Marcia Pankake wrote "A Prairie Home Companion Fold Song Book."
Alan Lomax lectured on the subject.
There is a NZ fold song website.
Shenandoah, American fold song, arr. James Erb.
"A spiritual is a type of African American fold song"

Fold song- A ballad, a ditty, a popular song. Used in Japanese translation.

?? Confusing.