Carla Bruni serenades an absent Mandela

Celebrities turn out to perform for South African statesman's anti-Aids charity – and a star-studded audience

Carla Bruni sang the pacifist anthem "Blowin' in the Wind" in her first public concert since she became the French First Lady in a star-studded concert for Nelson Mandela at the weekend.

A nervous-looking Ms Bruni, accompanied by The Eurythmics' Dave Stewart, won thunderous applause from an equally-celebrity-filled audience, which included her husband, President Nicolas Sarkozy, in the Radio City Music Hall in New York.

Ms Bruni had pledged that she would not make live appearances while she was First Lady of France but made an exception for the Mandela jamboree to mark the veteran anti-apartheid campaigner's 91st birthday.

Making her American concert debut, she said that she had chosen the Bob Dylan number as a "song by another famous activist".

She also sang a ballad of her own, "Quelqu'un m'a Dit" [Someone Told Me], which she announced, in English, was "not good for dancing. But it's good for dreaming." Among the other performers at the charity concert included Gloria Gaynor, Aretha Franklin and Cyndi Lauper.

The guest of honour was absent because his doctors have advised him not to travel long distances. The concert marked the first Mandela Day. The organisers, the Mandela Foundation, hope this will be celebrated annually on the South African leader's birthday to raise money for his anti-Aids charity and to remember his achievements.

Supporters were encouraged to give 67 minutes of the day for charitable work – 67 being the number of years that Mr Mandela worked for racial equality in South Africa. His campaign is called Campaign 46664 – his prison number while in jail.

There is no precedent for the First Lady of a large country singing at a pop concert. Ms Bruni looked somewhat unsure how to behave. She wore a chic black trouser suit and strummed her guitar but radiated a kind of political aloofness rather than a rock musician's bonhomie.

President Sarkozy and his wife and a posse of bodguards left the hall soon just after her performance to catch a plane back to Paris. She therefore missed the grand finale: Stevie Wonder singing "Happy Birthday".