I have seen a family-tree graphic of music from the viewpoint of the music that flowed out of African American Spirituals (AKA negro spirituals as they are known internationally). PM me an email address and if I can find the copy I stored on the hard disk, I can send it to you. Mudcat lacks photo-posting tools, but since it's not my work I wouldn't post it if we did.

PS welcome to Mudcat!

~Susan