Letta Mbulu was born in Soweto and, during her teens, she toured South Africa and then England with the musical King Kong. She returned to South Africa at the end of the tour but was soon forced into exile in the United States. While in the states she was invited to tour with Cannonball Adderly and soon thereafter joined forces with Harry Belafonte. Her relationship with Harry Belafonte became a rewarding musical venture that took Letta on several world tours. She married a fellow South African musician, Caiphus Semenya, whom she met while touring with King Kong and together they released many hits.
She has been a member of the prestigious Union of South African Artists, where she became exposed to folk, American Jazz and Brazilian music, and has worked with the likes of Michael Jackson. She also acted in the film Roots for which she received an Emmy award. Her other screen appearances include A warm December with Sidney Pottier and The Colour Purple. She is a founding member of the South African Artists United (SAAU) an organisation which was established in 1986. This organisation launched the musical Buwa that carried a political and historical theme with Letta in the leading role.
On their return to South Africa, Letta and Caiphus performed in the Unity '91 Festival that marked the first time they had shared a stage with other fellow musicians on home soil. In 1992 she released a new album entitled Not Yet Uhuru. The album was Letta's first to be recorded in South Africa since her return and it was arranged and produced by her multi-talented husband Caiphus.