Egging each other on: They have been billed as physical theatre, live art, mime, dance and oral Palestinian theatre. Naseem Khan gets a hold on dA dA dUMB

It was an unlikely spot - a series of gloomy concrete struts around the Grand Union Canal just at the point where it went underground, under a sombre Manchester tower block: unlikely, but, it turned out, fruitful, since there, in the summer of 1988, the two Martins (Coles and Gent) met when a number of performers gathered to make an experimental piece of work - 'Not a major success', recalls Coles with a wince. The result has been a five-year working partnership and dA dA dUMB, an innovative performance company.

dA dA dUMB defies categorisation, or certainly tries to. 'No, we are not physical theatre,' says Coles sternly; 'nor live art,' puts in Gent. And certainly not mime, even though they are currently appearing under the banner of the London International Mime Festival. Indeed, the work has appeared in all these guises and more - as dance (in Dance Umbrella), as theatre and even as part of a Jerusalem festival of oral Palestinian theatre.

But try and pin them down: dA dA dUMB productions usually consist of Gent and Coles alone in a non-text- based piece they have themselves devised. It will have a narrative thrust but will not tell a conventional story; it will have verve, originality and a certain surrealistic feel. Were it dissected, it would be found to have a single germinating idea at its core.

Chance and Ripeness (at the Young Vic until Saturday) centres on the word 'invention'. 'I was interested,' Coles elaborates, 'in the law of science that says every action has an opposite reaction.' And that, picked up Gent, led on to the principles of alchemy in which an element could be changed into its opposite, the ugly into the beautiful. Accident and coincidence became a focus of their talk and improvisations. And then, when they realised that their associative games were threatening to cast up a mass of diffuse and sprawling material, they fixed on a central act: how to boil an egg.

The menu for Chance and Ripeness sounds as if it contains all the ingredients for a dish of obscure confusion - two boffins, a large number of eggs, a series of faintly sinister experiments, a camping stove. In fact it has a clear and inexorable logic, a degree of deadpan hilarity and a finely- tuned inventiveness, albeit without any overt message.

The two men, in their early thirties, come from different worlds. Coles has worked frequently in contemporary dance while Gent started off as a structural engineer before turning to theatre. Their differences help in the devising process when they bounce ideas off each other rapidly and argue, often for weeks, before they even reach a rehearsal space - what they call 'interesting debates' rather than full-scale battles. All sorts of strange objects find their way into the creative soup - death cults, pendulums, magnetism. Gent protests ruefully that Coles always seems to be the one who says no. But then, suddenly, a synergy will arrive. 'There's a certain point when . . . ting] And we both know - right, we're off.'

dA dA dUMB in 'Chance and Ripeness', 8pm to 22 Jan, Young Vic, 66 The Cut, London SE1 (071-928 6363)

(Photograph omitted)