Legendary South-African choral group Ladysmith Black Mambazo have had a prolific career since being formed by Joseph Shabalala in the '60s. After collaborating with Paul Simon on 'Graceland', their breakthrough album was 'Shaka Zulu' (1987), produced by Simon. Many albums and awards later, they're still together and touring today.
A fascinating blend of traditional a capella Zulu singing, called isicathamiya (roughly 'on tiptoes'), and Christian gospel, the word that comes to mind to describe their music is immaculate. Besides being incredibly harmonious, these 10 voices have an awesome power, as also testified by their name: Black refers to a black ox, while Mambazo translates as 'axe', symbolic of their early days when they would 'chop down' everyone in singing competitions. (To complete the band's etymology: Ladysmith is the name of Shabalala's hometown.)