Oliver Mtukudzi: Hailing from Zimbabwe, songwriter, guitarist and vocalist Mtukudzi first worked as a professional musician when he joined the Wagon Wheels, a band that included Thomas Mapfumo, another South African artist with a strong social consciousness. Some 40-plus albums later, Tuku still sings songs that deal with economic and social issues, all delivered with a refreshing sense of optimism and humor. 9:15 p.m., Orchestra Hall at the Max. (Also 2 p.m. Saturday, Diversity Stage, Chene Park)