AFP - Legendary Argentine folk singer and activist Mercedes Sosa, who used her powerful voice to sing for the voiceless, died Sunday at the age of 74, a local hospital announced.
  
The singer, who had been suffering from various kidney and lung diseases, had been in intensive care at the hospital since September 18.
  
"Mercedes Sosa passed away this morning," said a brief hospital announcement released here Sunday. "We convey our condolences to members of her family and her loved ones."
  
Nicknamed "La Negra" because of her jet-black hair, Sosa was one of the lead exponents of the "Nueva Cancion," a musical style that combined ballads with folkloric instruments, with lyrics that often combined romantic themes with social issues.
  
During her long career that saw her produce 40 albums, Sosa collaborated with musicians ranging from Luciano Pavarotti, Sting, and Joan Baez to Latin stars such as Shakira, Caetano Veloso and Joan Manuel Serrat.
  
She performed in the Sistine Chapel at the Vatican in 1994, and to sold-out crowds at Carnegie Hall in New York in 2002 and at the Coliseum in Rome in 2002.
  
A UNICEF goodwill ambassador, her latest album "Cantora" is currently nominated for three Latin Grammy awards.
  
"I never thought that I would sing for a living," Sosa said in a recent interview.
  
Born into a humble home on July 9, 1935, in the northern Argentine province of Tucuman, Sosa -- who was half indigenous Aymara -- was strongly influenced by popular culture and traditional folk music.
  
With help from her husband, musician Manuel Oscar Matus, she recorded her first album in the early 1960s, and became known in Argentina after singing at a 1965 music festival in the city of Cordoba.
  
Sosa, a self-proclaimed progressive, went into exile during Argentina's 1976-1983 military regime.
  
One of Sosa's best known songs is "Gracias a la Vida," or "Thanks to Life," from a 1972 album honoring the late Chilean poet and singer Violeta Parra. The recording was further popularized in a slightly different version, with Sosa singing in a deeper voice, in the 1980s.
  
She also popularized songs written by Cubans Silvio Rodriguez and Pablo Milanes, as well as songs by Brazilian Milton Nascimento.