As soon as he could play, Mr. Gwangwa was swept up in the jazz boom in Sophiatown, a racially mixed Johannesburg neighborhood where a vibrant youth culture emerged in the postwar years.
Together with Mr. Masekela and the saxophonist Kippie Moeketsi, he journeyed to Cape Town to seek out Dollar Brand (later known as Abdullah Ibrahim), a young piano phenom whom musicians in both cities were talking about. When they found him, the Jazz Epistles were born: six blazing young talents, all fascinated by American bebop but intent on giving voice to the cosmopolitan imagination of young South Africans.
In 1960, police in the Sharpeville township massacred a group of protesters against apartheid restrictions. A harsh government crackdown followed in all realms of society. After touring with “King Kong” in London, Mr. Gwangwa remained abroad, eventually moving to New York to enroll at the Manhattan School of Music.
He roomed with Mr. Masekela for a time and became increasingly active in the milieu of A.N.C.-aligned expatriate artists. He helped to edit the speech that the poet Keorapetse Kgositsile, an old friend, wrote for the vocalist and activist Miriam Makeba to read before the United Nations in 1963. He was the arranger of a Grammy-winning album by Ms. Makeba and Harry Belafonte, and he performed at the 1965 “Sound of Africa” concert at Carnegie Hall, alongside Mr. Masekela, Ms. Makeba and others. He also led his own ensembles, including African Explosion, which released one album, “Who?” (1969).
Mr. Gwangwa’s apartment in New York became a meeting ground for fellow musicians and activists, fondly referred to as “the embassy.”
In 1976, after a stint in Atlanta, Mr. Gwangwa moved with his family to Gaborone, Botswana, where he founded Shakawe, a group of exiled South African jazz musicians, and became a member of the Medu Art Ensemble, an interdisciplinary collective engaged in the anti-apartheid struggle. In 1977, he appeared in Lagos, Nigeria, at the Second World Black and African Festival of Arts and Culture, known as Festac, a historic gathering of representatives from around the African continent and across the diaspora. Taking in the range of talent on hand, he decided to organize the South African performers into a unified multidisciplinary production. They were a hit.