The tall, thin girl from South Africa begins the song on a note so searingly high and pure that some students in the classroom of the Field School in Northwest Washington will recall having felt a chill.

This is what it sounds like when you are poor, from South Africa and singing for your life in one of the wealthiest communities in the Washington area.

Immediately, 11 of Elsa Nkuna's South African peers join her in a traditional dance, chanting, smiling, twirling, telling stories between songs, as students from America sit before them.

For the past four weeks, the youths from Winterveldt, South Africa, have participated in a cultural exchange here. They have been living with host families in Potomac and Bethesda and performing at schools and churches sometimes twice a day to raise money so they can attend college back home. Through it all, they've attempted to explain their culture and their country and the importance of song to both.

"When our country was ruled by an apartheid government, it was illegal to say anything ill about the government, " says Jabu Mfumba, 27, a member and a leader of the group. Song, he says, was a means of protest.

Now, the group is trying to sing its way out of poverty.

The South African township of Winterveldt, about 30 miles northwest of Pretoria, has a population of 700,000 and a 50 percent rate of unemployment. One in four people are infected with HIV/AIDS. Domestic violence is prevalent. There is little opportunity once a young person graduates from high school.

Since it was founded in 1999 by a South African doctor and nurse, the Bokamoso Youth Centre has been trying to broaden the horizons for the township's youth. Each year, the center selects 12 young people who have been trained in song and dance to travel to the United States for the month-long performance tour and to raise donations for scholarships through the exchange program.

In 2008, the center received $143,000 in pledges and donations through the exchange program. That covered 36 college scholarships.

"At the center, they get one meal a day," says Roy Barber, a teacher at St. Andrew's Episcopal School in Potomac. "The European Union built the facility. It is a big hall with a stage and room for sports. Funding is a struggle. The roof leaks. Sometimes the electricity is off, but they persist. A song they sing, 'I will never give up,' comes from the apartheid struggle."

A playwright and composer, Barber is president of the Bokamoso Youth Foundation. Each summer, Barber travels to Winterveldt to audition youths with Leslie Jacobson, a George Washington professor and vice president of the foundation.

"We are looking for youth cultural ambassadors," Jacobson says.

Students here are fascinated by the ambitions of the South African youth, as well as the "breathtaking" struggles and challenges they must overcome, says Jacobson, who teaches a course called "Theatre of Social Change."

"If you want to take a university class, there is no public transportation between Winterveldt and Pretoria. Only taxis or trains," she says. "I know young people in Winterveldt who get up at 5 in the morning so they can get to 8 or 9 o'clock class in Pretoria or Johannesburg or students who take classes who can't really afford the textbooks."

There is a certain urgency that drives the Bokamoso students. "Young people in more affluent cultures think, 'I missed this opportunity, another will come tomorrow.' In their community, they realize this is a big opportunity that may not come again."

When the music stops there are always questions, the sort you are asked repeatedly when you are from one of the poorest townships in South Africa and you are in America, singing for your life:

What do you think of America? Do you like it here? What is it like where you come from? What is the difference in the educational systems? Do you eat chicken? Do you have pizza? Do you have shopping malls?

The answers tend also to be the similar:

"Yes, South Africa is a civilized country. But it faces many challenges. We face many challenges where we are from. In Winterveldt, most people are very poor," says Mandla Sibanda, 19. "There are so many challenges: HIV, AIDS, teenage pregnancy, drug abuse. Many young people have hopes to go to college, but their parents cannot finance fees."

"Growing up in South Africa is different from the States," says Constance Mmaabiya, 21. "We grow up with the concept of Umbuntu. It means: 'I cannot be fully myself until I help you to be fully yourself.' "

Then the discussion at the Field School turns to misconceptions and cultural differences.

"When you are in South Africa, all you see are music videos," Mmaabiya says. "They portray a different picture of the United States. You see Beyonce videos. The hip-hop videos, they show people drinking and having fun and not working hard at all. People have a sense that Americans are so rich, and all they do is drink and have fun the whole time. But we see people here work very hard."

Says Nkuna: "When you talk to Americans, you have to look them straight. In South Africa, that is disrespectful. There, you must look down when you speak to your elders."

Another thing: "We find it strange when, if you are walking in the mall, people smile at you," Mmaabiya says. "They don't even know you, and they wave and smile. It's strange. In our country, you don't smile at a random person." The painted smile is a form of disrespect.

And this: "We say, thank you. Thank you. Here, they don't say thank you. If you give me a bottle of water, I will say thank you. If you do not say thank you, for me, my impression is you are not grateful. You should be grateful for everything you are given."

"Sometimes," says Lerato Mothamaha, "we annoy other people when we say thank you."

On Friday after the discussion, Mfumba stands at the front of a classroom. "We will teach singing and chanting, tools used to liberate our country."

On the board, he writes "Niya Ba Saba Na!," which means "Are you afraid?" in IsiZulu.

The response: "Hayi asibasabi siya bafuna!," which translates to: "We are not scared! We want them," referring to members of the apartheid government.

Mfumba tells the class, "People were angry and confused. This is not a happy song. You have to show aggressiveness and intensity in face."

Mfumba leads the chant. The Field School students follow. Mfumba stops.

"Remember," he says, "no smiling."

He writes on the board: "Siyaya epitori." ("We are going to Pretoria!")

You respond, "Siyaya. Siyaya. ("We are going! We are going!")

"When you sing, you must clinch your fist and move your knees."

The students begin to sing timidly. No! Mfumba shouts. No smiling. This is an angry song. He jumps fiercely in front of a girl whose face turns red. He shouts, "Siyaya epitori!" The girl shudders.

Soon the students are dancing the toyi-toyi, a protest dance, and chanting fiercely. After three minutes, Mfumba stops.

"You can imagine we have been singing three minutes and the breaths are hard. Can you imagine for those people [during apartheid] had to do this song the whole day from Winterveldt to Pretoria and back, singing the same song?"

Later, Nkuna sings again.

"I have gone to bed with an empty stomach, but I will live to harvest my success," she sings. The group joins her:

"I will never give up. In times of sorrow, I will never give up."