Living Costs, Tate Modern, London

This is a DV8 Physical Theatre show that expects obedient spectators, the way that site-specific promenade shows tend to expect them. Wendy Houstoun raps out, like an irritating gym teacher: "Move forward, move back, sit down. Quickly!" Back-up enforcement comes from other ushers, who include DV8's founding director, Lloyd Newson. They keep you in order as you progress from one video or physical event to another through Tate Modern. You are tagged with different coloured bracelets, given headphones to listen to the music, and late-comers are harangued.

My friend Leslie and I arrived a couple of minutes late, turning the evening into an interactive performance. While the audience was filing in, Leslie was sprinting from the Tube, her train held up by a suicide; as DV8 were starting, I was sprinting around outside, in search of Leslie. Perhaps Newson couldincorporate our act to liven up a show possessing some nice high points, but underwhelming stretches in between.

Ah, the stresses of modern life. Is that what the title, Living Costs, alludes to? Body image seems a preoccupation, echoing DV8's earlier production The Cost of Living. Fat and skinny, old and young, hairily masculine and smoothly feminine: they all appear dressed in plumes and sequins for a Busby Berkeley staircase tableau. Or maybe the title is an oblique attack on materialism in general and the art market in particular - and, by ungrateful extension, on the partnership between art and commercial sponsorship that has enabled this Tate initiative in artistic crossover. We hear remarks about need and greed, but none of it adds up to much.

The sections are living exhibits, presented in the building's spectacular setting (closed to the usual public for the occasion). High art confronts low art, paralleling the show's physical transition from ground to seventh level. There is the young, lippy Scot whose street-smart dancing is juxtaposed with the professional aesthetic of a conventional female dancer. There is the big-bellied man posing as a statue on one floor, while on the next are the elegant shadows of dancing limbs, accompanied by an opera singer.

The fashion models conveyed on twin escalators - "part of the Tate 2003 collection" - are effective; two human streams of graceful frozen poses, one going up, the other down. The circus couple, with their hoops and flames, inject a wistful poetry, especially when watched from far above, as two small figures lost in the vast space of the Turbine Hall. By the close we're on the top floor, for a brief sequence of elevated, classically shaped dance against the nocturnal backdrop of the City.

The final image is a surprise, filled with urbane, humorous magic. But that is not enough to save a show that is a tangle of inchoate ideas. Newson is adept at cohesive, tautly articulated themes, but this time he's defeated by an overambitious scale and diversity.

'Living Costs' ends tonight. DV8 tours with 'The Cost of Living', 12 July-29 Nov (020-7655 0977; www.dv8.co.uk)