Moving On | The Bridewell, London

Audiences for musicals tend to want to be comforted rather than challenged. They like hearing what they've heard before which explains the endless diet of revivals and the applause for the shameless practice of needless reprises, the trick whereby a composer turns a tune into a hit. Repetition is the name of the game, but where does that leave Stephen Sondheim? He's a revolutionary working in a reactionary form, his shows low on repeats.

Audiences for musicals tend to want to be comforted rather than challenged. They like hearing what they've heard before which explains the endless diet of revivals and the applause for the shameless practice of needless reprises, the trick whereby a composer turns a tune into a hit. Repetition is the name of the game, but where does that leave Stephen Sondheim? He's a revolutionary working in a reactionary form, his shows low on repeats.

The obvious exception is Side By Side By Sondheim, the compilation dedicated to reprising highlights of his career up to 1976. Given its success, it's no surprise that people have tried to, yes, repeat the formula with his now vast back catalogue. Cameron Mackintosh spent years doing just that, endlessly reworking Putting It Together - a project that boasted divas as grand as Diana Rigg, through Julie Andrews and Carol Burnett - all to no avail.

The latest attempt comes with the bonus of being devised and directed by David Kernan, progenitor (and sole male performer) of Side By Side, but he has, as one Sondheim lyric puts it, "lots of hills to climb". Chief of these is how to contextualise all of, or moments from, 42 disparate songs. His smartest move was to hire Sondheim as narrator, who appears on tape and in photographs splashed across the back of the set. His commentary, droll (if rather coy) autobiography and thoughtful observations about theme and subject matter, is infinitely preferably to the cheesy showbiz insincerity which bedevils the cabaret scene.

Sadly, Kernan hasn't banished that mode from the performances. The point about Sondheim is that he's a musical dramatist. Untimely ripped, the songs pose problems which these five performers don't always know how to solve. Linzi Hateley, not always the subtlest of singers, fares best, but the others, no matter how strong their voices (and they run a dangerously wide gamut), have that look behind the eyes which suggests that they themselves are unconvinced. Too often they stand holding bright toothpaste grins as if they've run out of lines but the camera is still rolling, and their bodies rarely come into play except to underline lyrics in the most literal ways. You see it in the giveaway symmetry. If someone's left arm rises to make a gesture, so does the right. Why? Because the singers are only vocally connected to the material, that's why.

Warren Carlyle contributes some neat choreography - the re-thought "Ah, Paree" is sharp and funny - but the dancing slips between pleasurable and effortful. Despite fine moments, notably the ensemble work, there's too much determination to be winning. It's only when everyone relaxes in the charming duets "I Do Like You" and "A Moment With You" or Angela Richards's beautifully simple "In Buddy's Eyes", that genuine warmth fills the air.

The dovetailing of different songs is extremely adroit and the well-played arrangements for piano and bass with heartfelt cello lines are often powerfully evocative. However, the tempos are sometimes painfully slow - "Sunday" almost grinds to a halt - and the performers have a habit of over-savouring every note. You get the feeling that everyone involved loves the material just a little too much.

To 19 Aug, 020-7936 3456