Sure, Bill Cosby's slick. But does his humour ever venture beyond the front door?

The one thing you have to say about Bill Cosby is that the guy is seriously cool. He doesn't bother playing a single UK date in 30 years of show business (who needs to impress the Brits to become one of the highest-paid entertainers in the world?); and, when he does finally show, he turns up as part of the Capital Radio Funk, Soul and Jazz Festival, touching down from the south of France on the afternoon of the gig in his private jet with absolutely none of the trappings of the on-the-road showbiz millionaire. Elton John, we learnt in Sunday night's kiss-and- tell rockumentary, tours with his own personal travelling hair stylist; Bill Cosby flies in with an entourage of none, on his tod, without so much as a publicity assistant in these showbiz days when even publicity assistants need publicity assistants. Presumably he pilots his own jet.

So here he was at the Royal Albert Hall, Billion Dollar Bill on a London stage for the first time ever, and what did he want to talk about? Come on, you've seen The Cosby Show. That's right. His wife. The kids. Marriage. The Family. Not that it wasn't ever anything less than 100 per cent smooth, and so laid-back he ended up lying on the stage, but we could have skipped the Oprah-style marital debate: "What is it he does makes you so angry you know he does it on purpose but you can't prove it?"

The material was never going to be anything other than highly autobiographical, but we could have done with occasionally stepping beyond the impassable barrier of the Cosbys' front door. The problem with Cosby's humour is that he seems terrified to play it any other way than safe, to present any facet of his character that might not be deemed entirely adorable.

You've only got to look at his plans for the US version of One Foot in the Grave, which include turning crabby old Victor Meldrew, one of comedy's great monsters, into A Lovable Guy. And it's not enough just to put it down to Americans and their notorious ability to kill British sitcoms stone-dead (remember what they did with Fawlty Towers? "Great show. Shame about the guy with the moustache"). It's simply that Cosby is sticking with a hit formula, a multi-million-dollar formula. It's The Cosby Show. It's Cosby without the "b".

This said, it takes some doing to hold most of the Albert Hall in thrall for the best part of two hours with tales of your wife's bathroom habits. Cosby's rich, melodic tones span yarn after yarn with the sense of pacing, structure and aura of relaxation that can only come from decades of performance. Amid the family history, some pearls shone through. On "the change" in marriage: "One morning I came down and there was nothing on the table. I said, 'Dear, where's my breakfast?' and she said, 'You ate it yesterday.' So I went to McDonald's and I wanna tell you, the people there are a lot friendlier."

Which was fine, but had the early Cosby, the contemporary of Richard Pryor, been here, he would have cracked his jaw yawning. In the final analysis, you simply felt that, when the audience erupted into a standing ovation, it was more a lifetime-achievement thing than a spontaneous reaction to a night of flawlessly executed but startlingly unoriginal material.