pdq, it's very difficult to properly credit a lot of early black gospel-blues because a lot of what the early bluesmen recorded WAS trad, in whole and/or in part, based on specific spirituals or on parts of them and with tunes from them. These bluesmen often claimed songwriting credit on their singles so they could get in on the stream of royalties the "white" composers and singers were enjoying via similar means. The more you listen to that roots music (the spirituals), the more obvious this becomes.... so obvious that although I no longer take the time to track down each and every instance, I do plan to cover that concept in an upcoming Spirituals workshop.

~Susan