I swiped the above audio clip from KurtP's post I've never heard it sung like this at his blog A Trainwreck in Maxwell. It a 1916 recording of 'Swing low, sweet chariot' by the Tuskegee Institute Singers. It. is from the Library of Congress collection.
As KurtP alludes to, the singers were probably the children or grandchildren of slaves, so this version is likely closer to the version slaves would have sung. The U.S. transatlantic slave trade was banned in 1787, with the signing of the constitution, which means the singers would have been only about 120 years removed from African born slaves.
I've been talking about the music of Mali in a series of posts; and how African music traveled to the New World via the slave trade, evolved there in the isolation of the Age of Sail, and then reflected back via records and the radio. The above piece comes towards the tail end of that isolation.
Listening to it, I was reminded of how Salif Keita (who we've met before in the post Ex-pats in Paris) sometimes intertwines his vocal lead with a backup choir of female singers in a similar manner -- almost a call and response, but not exactly. Below is a video showing an example. It is interesting to see the same vocal device used in the two songs.