Ladysmith Black Mambazo - Amazing Grace

They sang mostly in their native Zulu language, and they danced the dances of their people. Their harmonies were so tight, you could not differentiate individual voices - it was as if only one person was singing, in a tone so rich and so pure that the concert hall was filled with perfect melody. They sang about hope amidst suffering, the beauty of their homeland, their people's struggle for freedom, the need for all of us to come together to work for peace.

But when the lights dimmed and the audience clapped them back on stage for their last song, this is what they sang.