It took me years to realize that the New Orleans (black) jazz funeral mainstay "Glory Glory Hallelulia/When I Lay My Burden Down" has the exact same melody as the Appalachian (white) spiritual "Will The Circle Be Unbroken."

Since "Circle" is, at least in part, *about* a funeral ("my mother's"), it may have been consciously set to the melody of the pre-existing "Glory Glory." Just a theory...