Six years ago, Joseph Oyoo-popularly known as Gidigidi-was just a young slum dweller with no hope for the future or of ever getting a job. His main worry was where his next meal would come from as his retired father and housewife mother struggled to raise him and his nine siblings.

Despite the financial strain on his family, Gidigidi avoided the temptation of joining the urban youth gangs that dominated his slum neighbourhood of Dandora in Nairobi, Kenya's capital city. He decided instead to turn to music and teamed up with fellow musician Julius Owino-known by his stage name Majimaji-to form Gidigidi Majimaji, one of the country's most successful hip-hop bands.

But it wasn't until 2002 that the group's fortune changed forever. It was the height of election euphoria in Kenya and Gidigidi Majimaji had just released a chart-buster track called Unbwogable (slang for unbeatable), which contained lyrics praising some of the opposition leaders who were gaining popularity. The song became the anthem of the National Rainbow Coalition (NARC), a political alliance that won the elections and currently forms the government.

The duo became overnight celebrities as the song quickly reached the number-one spot on the music charts. In 2004, they were appointed by the United Nations Human Settlements Programme (UN-HABITAT) as Messengers of Truth, an esteemed position whose other appointees include K'naan from Canada and Awadi from Senegal. Gidigidi Majimaji even performed live at the second and third World Urban Forums, held respectively in Barcelona in September 2004 and Vancouver in June 2006. "If it wasn't for my music, I might have ended up as a gangster in Dandora", admitted Gidigidi during an interview. "Through my music, I have managed to put my brothers and sisters through school; it also paid for my own university education. My dream is to start a studio and training school for upcoming musicians from the slums of Nairobi."

Moses Mbasu, creator of Kenya's first hip-hop website (http://www.kenyanhiphop.com), feels that "since its formation in the South Bronx in New York in the 1970s, hip hop has always had a positive influence on kids from the urban centres of the world. Gidigidi Majimaji are a living symbol of how being born in a slum does not mean you cannot create change in your society. They are showing the world that making music is not only about showbiz; it is about taking the money you earn home and using it to benefit your community."

Urban youth music bands are springing up not only in the slums of Nairobi but in other parts of Africa as well, giving thousands of youth an opportunity to make their voices heard and earn a living. In the United Republic of Tanzania, youth from Dar es Salaam have created a local hip-hop industry known as Bongo Flava, which dominates the local television channels and has also gained enormous popularity in neighbouring Kenya.

In South Africa, a new genre of music known as kwaito has been emerging since the early 1990s among the country's young urban black population. Kwaito (derived from the Afrikaans word for angry) uses South African slang known as Isicamtho (a language associated with township gangs) to create a unique sound that incorporates traditional African music, jazz, gospel and rock. It is among South Africa's most popular musical genres today and has been touted as part of the country's renaissance. "Like hip hop in the United States, kwaito is not just music", writes journalist Simone Swink. "It is an expression and a validation of a way of life-the way South Africans dress, talk and dance. It is a street style as a lifestyle, where the music reflects life in the townships, much the same way hip hop mimics life in the American ghetto."

Whether kwaito will be a force for social change is debatable, but many musicians believe that the music helps South Africans to move away from the revolutionary lyrics of the apartheid era to a more optimistic beat. In 2003, a kwaito group, Natizea, told a Johannesburg-based magazine: "Kwaito is our way of contributing to change in this country. It is also a way to remind public opinion what the ghetto expects from change: jobs, better schools and peace on the streets."