Regarding Paul Simon's "I Know What I Know". . .
Paul Simon went to South Africa to make his Graceland album and so it has much Zulu influence. https://en.wikipedia.org/wiki/Graceland_(album) So the language is probably Zulu.*
Can anyone provide the chorus at :43-:56, apparently repeated exactly at 1:23-1:37? And then my next request would be to translate, but I can use Google translator.
"I Know What I Know" is based on music from an album by General M.D. Shirinda and the Gaza Sisters. Simon was attracted to their work due to the unusual style of guitar playing, as well as the "distinctive sound" of the women's voices. https://en.wikipedia.org/wiki/Graceland_(album) However this band is not listed under Zulu, it's listed as a Tsonga band.