The Last Five Years, Menier Chocolate Factory, London <!-- none onestar twostar threestar fourstar fivestar -->

The time of our married lives

There is nothing new about the play that reverses chronology, starting at the end and working backwards. Harold Pinter did it in Betrayal, and Stephen Sondheim did it, with tunes, in Merrily We Roll Along. But Jason Robert Brown's musical The Last Five Years goes a step further, throwing away the chronological rule-book altogether: starting at the end of a marriage, it zips about, song by song, backwards and forwards over five years, occasionally putting different periods on stage at the same time, before ending more or less where it began. The device adds complexity in terms of plotting - the audience has to pay attention to work out just where in the marriage we are at any given point (though Brown is fairly lavish with clues). But it also deprives the story of any sense of direction, while adding nothing in the way of emotional complexity.

The marriage in question is between Jamie, a writer, and Cathy, an actress. He is Jewish, she is not - a fact that is given a good deal of significance in an early number, "Shiksa Goddess", in which he sings that "I'm breaking my mother's heart". Later, though, religion comes to seem entirely incidental: the real cause of the rift between them is that he is a success and she is not.

We learn of his success (bidding war for his first novel, rave review by Updike in The New Yorker, reading tours and literary parties) and her years of struggle (playing summer stock in Ohio - "going slowly batty/ Forty miles east of Cincinnati" - and going through the ritual humiliations of auditioning). As his star waxes, he offers her patience and understanding, while she becomes increasingly demanding and whiney. Not surprisingly, he has an affair and, eventually, walks out. In outline, the story - clever young Jewish novelist, beautiful but neurotic shiksa - is reminiscent of a Philip Roth novel; but it's Roth stripped of anger, ambiguity, and reality.

The central problem is that the story is far too one-sided. Cathy isn't given any chance to show her generous, compassionate side. This problem is compounded by the way the music is divided up: Jamie gets all the big, roistering, crowd-pleasers - for example the comic list of Jewish girls, Rosens and Shapiros, in "Shiksa Goddess", and the gospel-tinged, macho celebration of "Moving Too Fast", in which he crows over his success. In "The Schmuel Song", he sings an entire mock-Yiddish folk-tale while Cathy has to sit back and look admiring and adoring for what seems like an eternity (this is ironic, given that the folk-tale is about the joy of being granted infinite time).

To be fair, Damian Humbley grabs the opportunities with both hands in a performance that is notable for some thoughtful acting as well as vocal strength. Lara Pulver, who plays Cathy, has less vocal individuality, but also less chance to extend her range - wistfulness seems to be the keynote of her songs. In her only really funny number, "Climbing Uphill", about auditioning, she pulls off the combination of eagerness to please, panic and disillusion very well.

It is a limitation, too, that the couple hardly interact. Most of the songs are solos - monologues, in effect - and even when the two are on stage together, most of the time one of them sings while the other listens. Perhaps this is intentional, meant to demonstrate a flaw at the heart of their marriage; but it feels more like a failure of nerve and technique.

Whatever my reservations about Brown's dramatic technique, he has undeniable facility as a songwriter; and Matthew White's production does him proud, with a revolving stage and excellent small orchestra packed ingeniously into the Menier Chocolate Factory. The downside of that ingenuity is that the first night was damnably hot - not so much for the audience (who were issued with battery-powered fans), as for the actors. They have to dance and belt out songs under the stage-lighting for 80 minutes non-stop: purely as a display of athletic stamina this deserves to be seen.

Until 30 September (020-7378 1712)