The day an egg stopped the rock-chick show
The Barbican's new exhibition features birds playing musical instruments – which leads to the occasional unexpected dramaPascal Wyse

guardian.co.uk, Tuesday 16 March 2010 20.00 GMT

Air guitar ... Céleste Boursier-Mougenot's Barbican installation. Photograph: Carl de Souza/AFP/Getty Images

There was a look of mild panic on the face of the steward at the Barbican's Curve gallery when she politely asked e

veryone to leave on Monday evening."I'm sorry, we are having a technical difficulty," she said.

Half an hour earlier, the only problem had been you couldn't hear the cymbals in Céleste Boursier-Mougenot's exhibition. They had microphones on them, but all you could hear was the guitar and bass. Oh, and the vocals; the soft, busy chatter of the live flock of zebra finches sharing the room with us. They are the players in Boursier-Mougenot's rock band, inadvertently plucking and scraping the strings of the guitars as they perch or take-off, or shuffle along the fretboard while preening.

At one point a finch appeared to be doing an experimental solo, as he weaved Marram grass around the bridge of a guitar; one man's Hendrix is another bird's doomed attempt at nest building. The loudspeaker in the far corner seemed to be a favourite place to take a crap, but hey, this is rock'n'roll.

Whatever Ozzy Osbourne did with a bat on stage doesn't come close to what happened next. To intakes of breath from the crowd, an egg was laid on one of the horizontally mounted Les Pauls. It rolled perilously close to the edge, but came to a halt. The collective wisdom seemed to be that no one should touch the egg: it would cause the mother to abandon it. So, we were ushered out while the bird expert was called. The band, meanwhile, played on.

"It's sort of abandoned anyway by not being laid in a nest," says naturalist writer and broadcaster Stephen Moss. But the perceived wisdom, he says, is misguided: "If you touch an egg in a nest, a bird will not abandon it. Birds have a strong instinct to incubate."

So what did happen? "The breeder has taken it back to the aviary for another bird to sit on," says a Barbican representative. "We've now installed boxes so if any of the birds want to nest they can. The gallery is not the right environment for baby birds, but the birds in the exhibition are happy in the environment."

I hope so. The Barbican says it has consulted both the breeders and City of London animal health inspectors to make sure this is not a damaging experience. But I can't help thinking I'd find accidentally being in an experimental rock band every time I got up to lay an egg a bit stressful.