DJ and broadcaster Rita Ray travels to South Africa, home to distinctive vocal harmonies that have travelled all over the world. Visiting Johannesburg, Durban and Cape Town, she discovers the extraordinary songs and harmonies that have given this country a voice abroad. They have often carried messages about inequality and injustice at home, resulting in beautiful music with a real sense of purpose.South Africa is a diverse nation, and each tribal group has its own musical traditions. Cutting-edge artists sing in ancient languages such as Xhosa, migrant workers stave off homesickness with traditional singing and dancing in the street, whilst four-part harmonies imported from the west are heard in every church, but given an unmistakable South African twist.