South African singer Miriam Makeba, one of Africa’s best known voices and a champion of the fight against apartheid, has died of a heart attack after a performance in Italy. She was 76.

Known as “Mama Africa” and the “Empress of African Song,” Makeba was the first black South African musician to gain international fame, winning renown in the United States in the 1950s with her sweeping vocals.

Makeba fell ill after a concert against organised crime in the southern Italian town of Baia Verde late Sunday, her publicist said. She died after being rushed to a clinic in the town of Castel Volturno.

“It was from a heart attack, but she had not been well for some time,” publicist Mark Lechat told Reuters. He said Makeba had also been suffering from arthritis.

South African radio stations paid tribute to Makeba, reading out text messages in praise of one of the best loved stars in the country and across the continent.

Makeba had spent 31 years in exile after openly speaking out against apartheid. One of her songs demanded the release of former South African President Nelson Mandela, who spent 27 years in jail fighting white-minority rule.

Makeba made popular fashion statements that stressed her African pride through hairstyles and traditional garb.

Makeba came from humble beginnings in a shantytown near Johannesburg. The former domestic servant first started to sing in her school choir and learned new songs by listening to recordings of American jazz artists like Ella Fitzgerald.

She mixed jazz with traditional African sounds and punctuated some songs with the clicks of her Xhosa language.

Makeba won attention on the international stage as lead singer for the South African band The Manhattan Brothers. In New York, she worked with Harry Belafonte.

Exiled after speaking out against apartheid, Makeba created classics such as “The Click Song” and “Pata Pata.”

While she won over millions on the stage, Makeba’s personal life was marred by tragedy. Makeba had said her first husband often beat her, and she left him after finding him in bed with her sister.

Makeba married American “black power” activist Stokely Carmichael in 1968 and they moved to the West African country of Guinea, but later split. She was divorced four times.