Early arrivals in Cape Town were Brian May and Roger Taylor from the British pop band Queen, whose lead singer Freddie Mercury died of AIDS.
They are arranging the concert on behalf of former South African president Nelson Mandela's 46664 campaign which calls on all governments to declare a global AIDS emergency.
The 85-year-old statesman was given the number 46664 in prison while serving a life sentence for his opposition to white minority rule.
"We lost our own singer to AIDS, so we have inside knowledge about what needs to be done when arranging an AIDS concert," Taylor said.
"I suppose it is serendipity that we got into this position. We are going to use our music to do something about this disease," he said.
The 29 November concert will feature Irish rocker Bono, US singer Beyonce Knowles, Irish pop band The Corrs, Paul McCartney and singer and songwriter Peter Gabriel.
Some 6500 people a day die from AIDS each day in Africa. The disease has so far killed 17 million people on the continent, while about 30 million Africans are infected with HIV and AIDS.
Some 40,000 people are due to attend the concert which will also be aired on television.
"We have lots of work to do, lots of artists are coming and technically this has to work," said May.
"We have lots of responsibility. We have made a commitment to Mr Mandela. We hope the visibility this concert creates will bring the world together in the fight against AIDS," he added.