Dancing jailbirds with legs up to their ears. A nightclub babe who kills her lover. A shyster lawyer as smooth and dark as an oil slick with an eye for the main chance. Yes, there is life beyond Albert Square.

There is more to an actor's existence than whining, "Do me some egg and chips, Ma!" through a permanent plume of cigarette smoke, more to it all than playing a pantomime villain with a fixed sneer and no saving graces.

John Altman has been in EastEnders since that familiar snare-drum shot first heralded the cheesey signature tune onto the small screen back in 1985.

As the laughably horrible Nick Cotton, he got off to a flying start by murdering one of Albert Square's residents before trying to poison his gossipy old hypochondriac mother Dot. Over the years, there's not much in the way of evil-doing that Nick Cotton hasn't turned his hand to. Stealing, lying, cheating, murdering, selling drugs to children and breaking his old mother's heart were all in a day's work for Nick. Naturally, this sort of behaviour obliged him to make himself scarce from the Square from time to time, which is good news for John Altman - he has the security of being in a long-running soap and the opportunity to go off and do other things.

Which is partly why we come to be sitting in Oxford's Old Fire Station Theatre on a wet Friday lunchtime.

For Chicago is coming to Oxford and John Altman is coming with it. Chicago the Musical is the Apollo Theatre's big Christmas show, and John Altman is the big telly name it is hoped will put more bums on seats.

"That's part of the thinking behind it, yeah - having a name in the show that people will recognise. But I think that this show itself will pull people in," he admits.

Earlier, we'd been given a finger-buffet preview of the musical banquet to come, with some of the cast, including Altman, running through a handful of the numbers which have captivated audiences across the globe.

So he's sitting sipping coffee in full theatrical fig, which in this case includes a made to measure dinner jacket, crisp , snowy cuffs and a precise, slick-backed hairstyle, which makes him look more like he's stepped out of a Chicago speakesay than a BBC soap.

"They haven't stinted with this production," he points out. "Everything's top class, down to the studs on this shirt. No corners have been cut. This is exactly the same show in that respect that you get in London's West End. Sometimes, when musicals like this go on tour, you end up with two keyboard players instead of a full band because of the economics. But this is immaculate - no detail has been skimped on and it's a piece of class."

John Altman's speaking voice is a sort of chocolatey-growl. It's hardly surprising to be reminded that among his other stage triumphs, he's also made a good fist of playing Bill Sykes in Oliver! What's perhaps less well known is that he once appeared in a punk band in Oxford with the actress Amanda Donahoe. "Can't remember where it was we played," he says. "Some little village outside Oxford, though." He still has his own on-off rock band called Resurrection and began by playing drums before switching to guitar. At one point, the music business looked like an attractive career possibility.

"But it's probably a cleaner life, as an actor," he grins, "and the rock world can be very fickle."

He's from Berkshire originally but went to school in High Wycombe. At 45, he's divorced, with a 15-year old daughter and an ex-wife with whom he's still good friends.

"Yeah, we all went out for the lunch the other day. It was fine."

He's signed a 12-month contract for Chicago, so it seems as if Albert Square will be a Nick Cotton free zone for the forseeable future.

Will he miss it?

"Nah, not really. The thing with Nick is that he's evolved into this total outcast and if he was to stick around too long every time, they'd have to start softening the edges to make him believeable. As it is, he's got no redeeming features whatsoever, has he?" he cackles. "Well," he says, after a second's thought, "I suppose he did stop short of administering the fatal dose of poison to his dear old mum and he did give his son Ashley his leather jacket..."

"But being in a run in something like Chicago means a change in lifestyle for me. I like to find somewhere to swim and a place to park the car so I can walk to the theatre each day."

So, come Deecember 18, if you come across a familiar-looking face walking in the direction of the Apollo Theatre with a gym bag, you'll soon Cotton to who it is, won't you?

John Altman - all the way from Albert Square to Chicago, via Oxford.