OK, Joe, I've been thinking even after you slammed me above (which you are continuing to do), and here you go:

17. Choral performances organized and presented by Black schools and colleges where songs originating in work settings were standardized (often including harmonies added to originally-solo melodoies for public (white) (paying) audiences. Songbook transcriptions of same; recordings of same in various media as time went on and technology made possible.

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There are other categories suggested by others' contributions in this thread (and thank you very much), that I'll give some continued thought to.

~Susan