Ladysmith Black Mambazo (LBM) is an a cappella group from South Africa. The group was founded in the early 1960s in the township of Ladysmith (KwaZulu-Natal). The Black in the name refers to, Black Ox ‘, which (traditionally) is the strongest animal on a (African) farm. Mambazo means ax ‘.
Here is their song Nkosu Sikelel l´africa
World Music - the Music Journey 
It makes me happy when I read such :) keep it up!!!
Also, the song is our national anthem :) not sure if you knew that. It has 5 languages in it, but this video has changed the last 25 seconds of the original. Glad you like it :)