My sense is that the majority of such songs have long since been grouped by what the song was used for, such as "Nego Spirituals" or "Hoeing Songs" and such. But what comes to mind is the remark made by an old timer who said something to the effect that while people had come up with a number of labels for the music from "way back when" like "oldtime", "folk", etc., "When I was comin' up, we just called it music."