American singer-songwriter Sixto Rodriguez, whose popularity in South Africa was the subject of the Oscar-winning documentary "Searching for Sugar Man," has passed away at the age of 81. Rodriguez, based in Detroit, was unaware of his immense popularity in South Africa during the 1970s, where his songs became anthems for the anti-apartheid movement. The documentary, released in 2012, followed two South African music fans on their quest to uncover Rodriguez's fate. Swedish filmmaker Malik Bendjelloul, who directed the documentary, described the story as a real-life fairy tale. Rodriguez's music, which depicted the struggles of the working class and the decline of society, resonated with many. Despite being considered a talent on par with Bob Dylan, Rodriguez's albums “Cold Facts” and "Coming from Reality" did not achieve commercial success in the United States. Following the release of the documentary, Rodriguez's fame soared, and he performed at prestigious music festivals such as Glastonbury and Montreux Jazz Festival. The cause of his death has not been disclosed, but it is known that he underwent an operation earlier this year to repair damage from a stroke. Rodriguez is survived by his three daughters.