Nina Simone at Womad Barbican Hall, London
In London, 10 years ago, for one of her rare live performances, Nina Simone kept fans on tenterhooks until 1am. Last Sunday night, waiting for Simone to headline Womad's "Global Spirit" weekend, conjecture buzzed around a mainly white Barbican audience beneficently applauding the Somalian support act, Maryam Mursal. Would Simone be late? Argumentative? Sozzled? Perform a couple of numbers and go? Or not bother to turn up at all?

It wouldn't be the first time in the 64-year-old African-American diva's chequered history if she did fail to show. Prodigiously, dazzlingly talented she may be. Reliable she ain't.

In the event, a standing ovation greeted a punctual and distinctly frail- looking Dr Simone, the recently dubbed Honorary Ambassador for the Ivory Coast, as she shuffled on in gold sequins, silver pumps and a floor-length fur. "Do ya like my coat?" she cackles provocatively, settling on her piano stool. Backed by a band led by her musical director of 32 years, Al Shackman - a man coping admirably with the diva's penchant for launching into whatever she feels like - Simone embarks on a series of rousing spirituals.

A request for "The Other Woman" ("What you say, sugar?") is delivered; a rowdy punter is furiously pummelled by those around him and turfed out.

"I Loves You Porgy", her 1959 hit, even has the band applauding. So what if she then disappears and leaves us with an extended drum solo? Tonight's crowd have come to worship at the Church of Saint Nina, and the occasional bum note, missed word or cracked vocal isn't gonna make the slightest bit of difference. The effort, and it is an effort, of merely rising from her stool fuels roars of approval.

They roar through a feminised version of the spookily autobiographical "My Way", complete with bongo accompaniment, and still the Ambassador keeps spoiling us. After leading the audience on "We Shall Overcome", the familiar, rewarding kerplunk of "My Baby Just Cares For Me" sends all into paroxysms of delight.

"Haven't we had a nice time?" she observes coquettishly. And, despite the evening's last-stand feel, promises we'll do it all again some time.

"World music"? Music wasn't the issue. Tonight was about paying respect to a legend.