On West End opening nights, it's customary to have some shenanigans while the assembled slebs take their seats. Even by these standards, there seemed a grave danger that this was going to turn into Side by Side by That Bloke off the Telly.

Could a mere three performers going through the repertoire of one of musical theatre's more challenging composer-lyricists really hope to compete with the offstage time-wasting antics?

Then, eventually, the confident opening chords from A Funny Thing Happened on the Way to the Forum's Comedy Tonight struck up and the magic worked: we were Stephen Sondheim's, rather than Vanessa Feltz's.

It's no wonder that this canny revue, which premiered in 1976, was responsible for nudging Sondheim out of his cult ghetto and into popular recognition. It's Sondheim with the difficult bits taken out, the memorable tunes and sharp lyrics from the likes of Company and Follies.

Thirty super songs are on offer and another half a dozen from A Little Night Music, his finest work, could easily have been added. What other contemporary (wo)man of musicals boasts such a back catalogue?

Even with this high-class content, there's still the tricky issue of what to do with it. It's an unashamedly old-fashioned format as, in between two pianos, three elegantly dressed actors sing a lot, dance a little and smile dutifully at the explanatory link lines provided by the Narrator (Christopher Cazenove for the first two weeks).

Alasdair Harvey and Abbie Osmon are excellent but, on this evidence, the fact that Josie Walker is not a household-name is a scandal. She moves effortlessly from big emotion (Send in the Clowns) to big laughs (Getting Married Today), with every phrase delivered in a pure, versatile voice.

Director Hannah Chissick wisely winds the key and lets the time-honoured revue concept run itself with minimum fuss.

Adam Cooper provides some nifty, yet low-key choreography; clever business with bar stools skilfully underscores the less-than-perfect relationship detailed in The Little Things You Do Together.

That Bloke off the Telly applauded vigorously, and so did I.

• Until 14 July (0870 040 0046).