Brazil’s Grupo Didá, is an extraordinary ensemble of Afro-Brazilian women who use music to fight against injustice and racial inequality. Producer Dan Rosenberg speaks with the group's founder, percussionist Adriana Portela, about how Didá is working to redefine gender roles in Salvador da Bahia, and anthropology professor Andrea Allen (University of Toronto) on the history of slavery in Brazil, and the horrific violence inflicted upon enslaved women.