Nelson Mandela, the revered South African icon who spent 27 years in prison, led his country to democracy and became its first black president, died on December 5 at the age of 95. Mandela inspired a generation of activists, so it's befitting that the cast of Broadway's The Lion King, including native South African Ron Kunene, headed over to GMA on December 6 to pay tribute to the lost leader. "The legacy of Nelson Mandela is going to be a test because we have to perpetuate his vibrant vision of non-racial democratic society," says Kunene. Watch the cast's moving performance of "One by One" in the clip below.