Interesting early study by Paul Oliver, known blues researcher, looking at African musical elements related to [rural] blues structure. The author looks at a lot of previous sociological, musicological, anthropological research into "African" music(s) & culture, some which come to contradictory conclusions. He draws some comparisons between some elements but admits there needs to be further research & clarification about the actual demography of slaves brought to the "New World," since there are distinct differences between people, music and culture on the Coast & in the Interior of the continent.
In my opinion, there is a failure of the author to only refer to "jazz" in its New Orleans/"Dixieland? forms, instead of noting parallels with the progressive, modern & "free jazz" streams in the "jazz" idiom.