When Thembi Nyandeni speaks of apartheid, the passion ignited by repressed memories rises in her voice. Then, you could be arrested just for being black. And this was our country, she says with quietly devastating authority. This South African has experienced mankind at its worst -- men who delight in subjugating and humiliating others simply because of their skin color. But she is still positive, not to mention successful. Nyandeni starred in Tsotsi -- the recent Academy Award winner for Best Foreign Language Film -- before cocreating Umoja: The Spirit of Togetherness. A major hit throughout Europe and her homeland, Umoja is an exuberant musical that tells the turbulent history of South Africa through native rhythms and dances. It is not a play where you wind up crying and depressed. You learn from it, Nyandeni explains. The audience will discover the eleven languages and cultures that coexist there, while the performers themselves enjoy a unique kind of education. Nyandeni and cocreator Todd Twala personally selected the cast. I picked them up in the street, most of them. They did not even know how talented they were. That low self-esteem is gone now. They are so confident, she says with a note of well-deserved pride. Umoja opens tonight at 8:00 at the Gusman Center for the Performing Arts, 174 E. Flagler St., Miami. Tickets cost $20. Call 305-358-5885, or visit www.umojatour.com.