Dumisani Dlamini had planned to be a plumber in his native Durban, South Africa. But fate, or luck, or something, took him one night to a party where the playwright and director Mbongeni Ngema saw him dance, and the next day he was on his way to Broadway. Of course, there were many stops along the way. At the time Dlamini realized only that he had a chance to leave his plumbing course and his township in Durban for Johannesburg, over 300 miles away, and a new life learning the skills of the theater. He was barely 22, and had no idea that the raw talent he had in his slight young body would lead him not only to the stage in South Africa, but to New York in the musical "Sarafina!". Although there is still only a chance the show may tour, it is possible to get a taste of it in a new documentary, "Voices of Sarafina!," which opens today at the Biograph. "Sarafina!" opened at Lincoln Center in October 1987 and moved to Broadway a few months later, captivating New Yorkers with its compelling music and with the beauty and talent of its performers, who ranged in age from 15 to their early twenties. Audiences and critics overlooked the sometimes clumsy dramatic structure, emotionally snared as they were by the messages, both direct and implied, delivered by the young black cast from South Africa. The production, based on tales of oppression and brutality acted out by people who have experienced it, offers audiences an experience on many levels; it transcends its source material through the natural theatricality of the performers, and is laced with a joy that at first seems unlikely -- possibly even unseemly -- to an American audience. "We wanted to bring township theater to America," said Duma Ndlovu, a producer instrumental in bringing the production to Lincoln Center. "When I came to this country 10 years ago I found that Athol Fugard was the only thing people know of South Africa. He is wonderful, but he is white: he speaks to the guilty liberal. His plays tend to be depressing, with an air of hopelessness. The township theater is more representative of what is going on in South Africa. It is joy in spite of suffering, a sense of hope in the exuberance of the music. It comes from a spirit of survival. "Policemen can come to a township and spray tear gas and shoot people, and people come and take the bodies and they disappear, and a few hours later the spirit is back. You cannot break that spirit." But the spirit of the young singers and dancers in "Sarafina!" has been buffeted by other feelings as well over the last two and a half years, primarily an intense and almost palpable homesickness. For all the wickedness and misery they see in their homeland, they long for it and their families so much they have enormous telephone bills from calling home. Their lives in New York have been fairly circumscribed by eight performances a week. The company lives in a hotel; a few have kept up their schooling with tutors. "After the show we stay up until 5 a.m. at the hotel," said Dlamini. "Then we sleep until it is time to go to the theater." Ngema, previously known to Washington audiences as one of the two author/performers of "Woza Albert!" at Arena Stage in 1984, auditioned young people all over South Africa to find the 20 actors and seven musicians who worked with him for eight months creating "Sarafina!". They all lived in an old hotel, went to school and became a family for each other, a community that took on even more importance when they came to New York. At the same time Ngema was training their voices and bodies, he was also crystallizing their political role as unofficial "ambassadors" of their people. The documentary, which was directed by British-born Nigel Noble, includes a scene where Ngema reminds them of this extratheatrical role, and tells them what answers to give to various questions Americans have for them. (When they ask "what can we do to help change South Africa" tell them to "stop the American government from supporting Pretoria," he says.) When Dlamini's mother died a week before the Broadway opening, he was deemed irreplaceable and did not fly home for her funeral. "{Ngema} said to him he was now a man, and a man must sometimes do things that are very difficult," said Ndlovu. "Do we let him go back home and not open on Broadway?" "When we came to New York my mother wrote me, 'I am so proud of you. When I walk through the township I feel like the mother of a star; I feel young,' " said Dlamini sadly. "I carried her letter with me to read over and over. I had taken with me the sizes of the dress and shoes I was going to buy for her ... My life changed." Dlamini recently returned from a two-week vacation at home; he spent some of the time talking with his relatives about his mother and her death. But he holds no grudge against Ngema. "He is like our father," he said. The method of producing "Sarafina!" with the company living and working together, might seem alien to an American. Indeed, one American actress, hired under U.S. Actors Equity rules when the show moved to Broadway, left after complaining to the union that Ngema hit her during a rehearsal, "a sharp blow to my back," according to an account in The New York Times. Ngema said he "patted her on the back with my open hand" in an effort to "show them how you respond to pain." Equity negotiated a settlement with Lincoln Center over the dispute. Another American actress, Charnele Dozier Brown, continued with the company without any apparent difficulty. But even though Dlamini frequently consulted with Ndlovu in Zulu before answering a question during a recent interview, it was apparent that he is an artist first and an "ambassador" second. There are scenes in the film, too, that reveal the cast as essentially young people focused by their talent as much as anything else. There are shots of fuzzy bedroom slippers; of a girl sucking her thumb; and an emotional group collapse at the sight backstage of Miriam Makeba, the exiled South African singer they had heard of as a mythical figure they had never dreamed of being able to meet. Midway through a long day in Washington, Dlamini showed obvious signs of fatigue and petulance, uncensored by any false front of political duty. And he has no desire to stay in this country, where to his young eyes the freedom to speak is counterbalanced by the homelessness, racial prejudice, drug abuse and crime he has glimpsed. "We are oppressed," he said. "But we have hope."