Music from Nigeria was recorded by Robert G Armstrong, professor of linguistics and director of the Institute of African studies at the University of Ibadan.An online collection of early educational public radio content from the National Association of Educational Broadcasters (NAEB).
https://www.unlockingtheairwaves.org/programs/music-from-nigeria/
Music From Nigeria #3
While it is certainly true that percussion percussion instruments are of fundamental importance in African music, it must be realized that there are very important African musical styles which are song unaccompanied—a cappella as it were. And in this program we're going to listen to two different styles of this kind of unaccompanied vocal music.