In fact, the music of the “Graceland” album represented a unified black South African culture, even though it came from many different tribal heritages. “The Boy in the Bubble” is an example of the modal accordion music of the Sotho people. “I Know What I Know” is Shangaan in origin. “Homeless” is Zulu choral music, while “Diamonds on the Soles of Her Shoes,” “Gumboots” and “You Can Call Me Al” were township jive songs, urban grooves that were straight from the streets of Soweto, where people of different ethnic origins coexisted under the boot of a racist South African government. “Graceland” was united by the joy of shared music and the sorrow of apartheid.

On Feb. 11, 1990, Mr. Mandela was finally released from prison, and, in 1992, the “Graceland” tour went to South Africa. This was an enormously emotional event for all of us, but particularly for Hugh and Miriam, who were free at last to go home. A reception in our honor was given by the A.N.C. and hosted by Mr. Mandela, where I introduced him to Mr. Shabalala. One was a Xhosa and one a Zulu, but the men embraced, and Mr. Mandela called Ladysmith Black Mambazo “South Africa’s cultural ambassadors.” In 1993, they accompanied Madiba when he received the Nobel Peace Prize.

It was Mr. Mandela’s nature to bring people together, not to separate them by tribe or race. In his presidential inaugural address, he famously said: “Peace to you all, Black, White, Yellow, Red, Small, Big. Peace!”

For the 25th anniversary of the release of “Graceland,” in 2012, our old troupe reunited. Sadly, it was without Miriam, who died in 2008. As it happened, we performed in Amsterdam on July 18, Mr. Mandela’s birthday. As Hugh came to the mike to perform “Bring Him Back Home,” he introduced the song with these words: “The beautiful old men who negotiated the way to our freedom in South Africa are now very aged, and some of them have already left us. But we’d like to start by asking you to shake some serious booty for those old men and for Nelson Mandela, who is 94 years old today!”

That evening at dinner, Hugh was reminiscing about the Mandela he knew as a friend and inspirational figure. He said he’d been talking to Mr. Mandela on the phone, and when they hung up, he walked directly to the piano and wrote “Bring Him Back Home.” Another night, Hugh told me, Mr. Mandela called to tell him that he was concerned about Miriam’s health, that she wasn’t taking care of herself.