NINA SIMONE finishes another song, totters to the front of the stage and stands, fixing the audience with a gaze that's as intent as it is ambiguous. Sitting at the piano with profile to the audience she can carry off an air of the 'professional performer', but front on she looks... bemused? the teeniest bit deranged? resentful? embittered? Pick your interpretation, but one thing you can't deny — something ain't exactly right.

Of all the 'moving musical monument' performances there's something a little special about a Nina Simone performance — a syndrome entirely different to the halo of excitement/disbelief that surrounds the 'still can's like James Brown or Curtis Mayfield. In Nina's case (excuse the insufferable presumption of first name intimacy, it was catching at Ronnie's) it's less a matter of what she can do and more one of what on earth will she do?

Of course most of Simone's audiences thoroughly deserve a jolt or so — which adds the further intriguing dimension of whether or not the whole thing is a colossal wind-up, contrived by the Artist to knock her dotage-doting crowd out of their complacency.

This time round, with a ticket price of £12.50, the audience was younger than usual, but no less sick-making."'Mr Bojangles'!" one cloth-eared retard from the bar insisted on shouting at the end of each song, "'Just Like A Woman'!" a simple-minded female counterpart would rejoin from the other side of the room. Surprisingly in this situation Nina Simone decided, if not to play it straight, at least to indulge in a more subtle game or irony than might have been expected.

With the Ronnie Scott quintet backing, plus a musician of Simone's own to play organ and assist on vocals when higher notes threatened to expose the increasing fragility of her voice, the songs were unpredictable only in their predictability. What's more, she managed to finish virtually all of them, despite the occasional stop to complain that the band were playing to fast.

All the same there was a certain bizarreness which skirted the event. It showed in Nina's long stares into a vaguely embarrassed audience, in her indulgent pauses to allow the feebleminded to shout the inevitable (mainly tasteless) requests and in her sudden whim to relent to one of them with a hurried version of 'My Baby Just Cares For Me'. Above all there was the strange idea of Simone winding up the first set with a jolting calypso beat promising "We've another set to do for you tonight", then returning to perform practically the same songs all over again.

"Play something different," shouts the voice from the bar.

"Different from what?" the quietly menacing reply comes after a long pause. The audience is not totally silent.

"Different from the first set," the voice returns, a little sheepishly.

"No I won't play anything different," Simone replies exasperatedly, "I'm tired."

That edge of unease also manifested itself in the songs — in the strikingly bitter 'Just A Stupid Dog To Them', dedicated to the North American record industry, and especially in the black humour of her adaptation of Gilbert O'Sullivan's (???) 'Alone Again Naturally'. "This is about my father's passing," she introduced this bizarre episode, leaving the audience unsure whether to laugh or look concerned as she sang lines like "When I needed him the most/He was already a ghost."

Nina Simone still has full grip of the art of the squirm, and she's using it now with finer balance — she may never be so effective again.