The outdoor show in London's Hyde Park opened in eclectic style with Jivan Gasparyan, an Armenian master of the duduk wooden flute, followed by British band Razorlight.
Organizers said Bono and The Edge from the Irish band U2 had recorded a version of "Happy Birthday" that would be shown on big screens during the show.
Winehouse, whose participation was in doubt when she was hospitalized last week after collapsing at home, was due to end the concert by leading a rendition of the Specials' 1984 anthem "Free Nelson Mandela."
Proceeds from the show - which organizers hope would be attended by 46,664 people
- will go to 46664, the AIDS charity named for the number Mandela wore while imprisoned for opposing South Africa's apartheid regime.
Mandela was released from prison in 1990 after 27 years behind bars, and was elected South Africa's first black president in 1994. He retired from politics in 1999 and has since campaigned to prevent the spread of AIDS.
Josh Groban and the Soweto Gospel Choir were also lined up for the event, hosted by Will Smith and held to mark Mandela's birthday on July 18.
It also came 20 years after a 70th birthday concert at Wembley Stadium that helped press South Africa's apartheid authorities for Mandela's freedom.
Queen guitarist Brian May said the event was "as important and as joyful as anything we've done in our lives, and has a great serious significance as well."
"It's very much about spreading Nelson Mandela's message to the next generation, and I'm very happy to be a part of it," May said.
Many who turned out on a cool, blustery London evening said they had come to see Mandela rather than any particular act.
