Paul Simon has compared his return to South Africa to a family reunion - musical brothers getting back together after decades apart.

Documentary Under African Skies has premiered at the Sundance Film Festival, chronicling the creation of his album Graceland, its overnight success and the furor it caused, as critics accused Paul of impeding progress to abolish South Africa's system of racial segregation known as apartheid.

The 70-year-old star recalls his trip to South Africa last summer, to commemorate the 25th anniversary of the album, as far more joyous occasion than some earlier travels on behalf of the record.

Paul said he was surprised by protests that sprang up on his Graceland tour in the 1980s. But looking back, he said the album and tour with South African musicians raised awareness that helped end apartheid in the 1990s.

"Once I saw it had an immediate acceptance and that people loved it and had great affection for the music, I thought that the tour and the album were going to be a very effective way of showing just how evil apartheid was," Paul said in an interview alongside Under African Skies director Joe Berlinger.

Critics charged that the tour violated a United Nations cultural ban meant to pressure South Africa's white minority into doing away with government policies of segregation against blacks.

There were protests and even bomb threats, resulting in tight security as the tour progressed around the world.

Even today, there is lingering bitterness against Paul. Under African Skies includes a sometimes-uneasy exchange last summer between him and Dali Tambo, the son of African National Congress leader Oliver Tambo and the founder of Artists Against Apartheid.

The joint interview helped clear the air between Paul and Dali, who ended their meeting with a warm hug on camera.