Of all the raw and compelling voices in Joe Berlinger’s must-see documentary, “Under African Skies,” about the making of Paul Simon’s classic “Graceland” album in South Africa in 1985 — and his reunion with the same African artists 25 years later — my favorite is that of Graceland bass player Bakithi Kumalo. He tells about that day in 1985 when he met Simon in a Johannesburg recording studio:

“I was just working as a mechanic,” says Kumalo, “and one day I got this call from the boss and he said, ‘Hey, Paul Simon is in town, you know, and he’s looking for some musicians.’ And I said, ‘Paul Simon, who is Paul Simon?’ I mean I had no idea. And then the guy tried to explain to me. He’s singing all the songs. You know, like the songs from Simon and Garfunkel. And I’m like, ‘It doesn’t ring a bell.’ And then I take my bass and I go to the studio and so I meet Paul and Roy Halee, the engineer, and they’re like ‘Hey, man, let’s, you know, let’s play some.’ We’d play a chord — Paul would smile ... and then he’ll stop and change it. We didn’t know why is he changing? But he needed another part there that we didn’t know. Then he’ll break and give us different chords, and then we learned different things, and it was like going back to music school.”

Watching this film is, indeed, like going to music school and much more. For many, it will be going back to the first time they really heard the unique harmonies and rhythms of African music — thanks to “Graceland.” For some, it will be going inside the studio of one the most creative musicians of our time, watching him probing and experimenting with the styles, voices and melodies of South African musicians and melding them with chords and lyrics dancing in his own head into songs that we’ve been humming ever since. Who knew she had diamonds on the soles of her shoes?

But what intrigued me was going back to the politics of the mid-1980s, when South African apartheid was at its most vicious, prompting the African National Congress, or A.N.C., to call for a total diplomatic, economic, sports and cultural boycott.

This was before the Internet, globalization, iTunes and YouTube. Simon was drawn into South African music by a cassette tape someone sent him of the Boyoyo Boys. The musician in him insisted on following that sound to its origins, politics be damned. By daring to ignore the cultural boycott to make Graceland, he helped globalize the talents and sounds of a group of South African musicians the old-fashioned way — one concert and album at a time — and, in the process, empowered those artists in ways no liberation movement ever could.

Today, the Boyoyo Boys would have just cut a YouTube video and globalized themselves. But that wasn’t possible back then. Still, did Simon have the right, and was he right, to do what he did?
Interwoven through the film is an encounter, 25 years after the events, between Simon and Dali Tambo, the South African co-founder of Artists Against Apartheid, which imposed the cultural boycott.

“I think he had a great creative idea to mix his music and his rhythms and his ingenuity with some that he had found in South Africa,” Tambo recalls. “But, at that moment in time, it was not helpful. ... We were fighting for our land, for our identity. We had a job to do, and it was a serious job. And we saw Paul Simon coming as a threat ... because it was not sanctioned ... by the liberation movement.”

Simon, a friend of mine, was appalled by apartheid, but he bristled at the notion that, in collaborating with black South African artists on a synthesis that elevated their music and talents onto a world stage, he was hurting their national cause.

“When the artist gets into some sort of disagreement with politics,” Simon asks in the film, “why are the politicians designated to be the ones to tell us, the artists, what to do and we’re supposed to follow — otherwise we’re not good citizens or we’re not good?”

In the end, Simon and Tambo work through it all in the film and affirm that neither meant to hurt the other’s cause. Indeed, the A.N.C. has invited Simon and the Graceland band to perform for its centenary. But the just-released film (which will be shown at New York’s Ziegfeld Theater on Tuesday) leaves no doubt where the South African musicians stood.

Recalling their world tour with Simon after Graceland became a hit, saxophonist Barney Rachabane remarks: “In South Africa, we had no opportunity. We could only play in the townships. We couldn’t play in town in the beautiful nightclubs. You could have dreams, but they [could] never come true. It really destroys you. But Graceland opened my eyes and set a tone of hope in my life.”
Added guitarist, John Selolwane, “I remember when we were on tour and especially in Europe during the winter times. Every time Black Mambazo went on that stage and started singing, I would feel tears coming. I’m like, ‘Here I am. I’m an African boy. I’m in the middle of the snow and ... there are 50,000 people filled up in the stadium,’ and I would be crying. I’m like, ‘Damn, we are really seeing the world.’ ”