Emma linked the show for the "Jubilee Songs, Fisk Jubilee Singers" thread.

We can only guess at the sound of the original Jubilee Singers, but I had a feeling that the choir in the radio version of the play might have been close.
The lyrics in Marsh - Pike are rather hymn-like, as one would expect after changes made by their mentors at Fisk. Spirituals and gospel songs as currently sung are quite different. The Jubilee Singers also adapted some songs used at Hampton, where dialect was freely used.