It is street music, called Kwela. This word, Kwela is taken from the Zulu language, meaning to "get up." So, you would "get up" to dance in the local bars, or "shebeens," which were similar to the American speakeasies during the prohibition era. The origins of this style comes from "township music," a genre of music created by musicians residing in government housing during the Apartheid in South Africa during the 1950's.
Kwela music has an instrumental leader: the tin whistle. This was of real interest to me. I never came across whistle music, except in Ireland, Scotland, and the Celtic regions of Spain and France. Apparently, whistles of all kinds were traditionally played in the northern areas of South Africa. The whistles were also economical and easy to travel with, but more importantly, they served as a strong solo instrument (and gee, isn't that the truth). These traditional melodies thus translated into this Kwela style, with it's footwork heavy in American jazz swing forms supported by a three chord progression: C-F-C-G7.
(This clip above shows Willard Cele from the 1951 movie, The Magic Garden.)