What I can tell you is that these performances are for the tourists. They were in touristy parts of Cape Town where there was a lot of shopping happening: the Waterfront and Green Market Square. These are folks that get up in the morning, put on their costumes and go dance for tips. And it's nice that they do, because in Cape Town you don't really get a feeling of much traditional culture, it's a very modern and European city.
Tourists were constantly joining these ladies so that they could have pictures taken with them. It was a little annoying as I just wanted to watch them perform. I really enjoyed their interlocking rhythmic and melodic chanting. It was very cool.
I passed them a couple hours later and they were sitting and singing. It was hot, and they were tired. They were cute ladies.
If you know anything about these performances, please let me know.