On one of her early trips to Africa for her charity Keep a Child Alive, Alicia Keys received some blunt advice from an impoverished young boy. "He told me, 'You or anyone should really come live with me for a week,'" says Keys. "'No makeup. No nice clothes. And let me know what you think.'" That's exactly what she did in Soweto, a suburb of Johannesburg, where she visited young people whose lives had been devastated by AIDS to figure out how she could help. "The only place for us to talk was the concrete floor of the train station," says Katlego, one of the South African teens who met with Keys. "But Alicia just sat down like the rest of us! That surprised me. We talked for hours and hours. It was a day that changed my life forever."

The Grammy-winning singer, who launched her charity (keepachild alive.org) with philanthropist Leigh Blake in 2003, is being credited with changing thousands of lives by providing anti-retroviral drugs, food and community aid programs to those with HIV/AIDS in Africa. Their organization has helped upward of 250,000 people, and Keys, 29, has raised $20 million and counting. Her crusade began after her first trip to Africa in 2002. "There were so many mothers with the disease, worried their children would have it and unable to afford the medicine they needed," she says. "I knew I couldn't go home and pretend I never saw the things I did." Her desire to focus on giving back so early in her career deeply impressed her partner. "For her to have taken this on at the very start was quite risky," says Blake. "But Alicia has no ego in it. Just compassion."

With the help of the AIDS-fighting drugs her organization provides, "You see people go from the verge of death to being happy, funny and hopeful. It's spectacular, " says Keys. Adds Blake: "People are absolutely reborn on these drugs." But their organization's work goes beyond helping those battling the disease. "It's called Keep a Child Alive, but they don't just keep children alive," says Katlego, now 20 (whose name has been changed to preserve her anonymity). "They keep mothers and sisters and brothers alive. They keep families alive." Though not HIV-positive herself, Katlego lost her mother to the illness and is now leading her household of six with support from the organization while also going to school.

"[My family] went to bed hungry. We needed food, school supplies, everything," she says. "It's hard to dream when you're worried where your next meal is coming from. But now that's a thing of the past." Keys and Katlego have shared lighter moments together too. "We spoke about Hollywood, and I asked her, 'When you look at magazines, how are celebrities so perfect?'" Katlego recalls, adding with a laugh, "She told me that when she started out, she posed the wrong way and had no idea what she was doing!"

The singer's ongoing work with Keep a Child Alive includes putting together the annual Black Ball fund-raiser, overseeing a clinic and an orphanage that the charity built and keeping in touch via e-mail with young people she's met in Africa whom she calls "an extended family." Next up? Trips to Rwanda, possibly India and back to South Africa, where one young woman is looking forward to a reunion. "I have grown so much since we met," says Katlego with a smile. "I want her to see where I am with my life."

OPRAH AND PEOPLE MAGAZINE

SALUTE HEROES ACROSS AMERICA WEDNESDAY, NOV. 25, 2009