Milo J, Cazzu, and more stars are embracing music and traditions of the Argentine countryside, staving off pop homogenization and sharing their history with the world

The Argentine singer Soledad Pastorutti never anticipated that her debut at the Cosquín National Folklore Festival, in 1996, would be historic. At just 15 years old, she took the hallowed stage at Próspero Molina Grand Plaza, where iconic troubadours such as Los Chalchaleros and Mercedes Sosa had shot to fame since the 1960s — some as keepers of rural wisdom, and others as interrogators of the powerful. The teenager performed three songs including the romantic zamba “Salteñita de los Valles” and the stirring chacarera “A Don Ata,” the latter a tribute to one of the godfathers of South American folklore, Atahualpa Yupanqui.

Soledad’s confident vibrato was greeted with cheers and she celebrated by whirling her poncho in a victorious gesture that remains her signature to this day.…