In the old Victorian hall at Upper Campfield Market there's a film by Gillian Wearing which shows women in flowered dresses puckering their lips and hooting like owls as they attempt to play "I'd Like to Teach the World to Sing" by blowing into empty bottles. It is a telling little vignette, a comment on shared hopes and futile gestures. Meanwhile, down in the Chinese Arts Centre, Matt Collishaw has set up a delayed- action recording device to play back the tweetings of a cage full of live budgies, so the birds can have conversations with themselves. Elsewhere there are fibre-glass monsters, hair shirts, paintings with elephant dung stuck on them, and lots of photographs, films and videos in which the penis looms large. Hermione Wiltshire has filmed a souffle rising in an oven, and called it Casanova, in homage to the Priapic Italian. This time around, the show has lots of willies.
It has also got balls. The show is more than just a plodding round-up of our brightest hopes: and bright is hardly the term for the most memorable work here - there's an edge of darkness, a seriousness, a sense of disquiet that slowly impresses itself as one makes one's way from venue to venue.
The tenor of the exhibition also runs counter to the frenetic Challenge Anneka pace and the road-show atmosphere laid on for the professional art hounds at the opening. And if much of the work has been seen before elsewhere, the conjunctions and sight-lines drawn by the selectors resist the illusion that new British art - like Britpop - is all jangly one-liners, interesting haircuts and a lot of hot air about life and death and other artistically meaningful issues.
While the supposed renaissance of the music scene is vaunted for its retro sartorial style, kitchen-sink lyrics and twanging popster melodies, the attraction of new British art is harder to define. Is there substance beyond the hype - or is the current wave of internationally applauded young British art just another load of over- promoted Brat-pap?
Damien Hirst, who directed the video of Blur's "Country House", is given a prominent place in the exhibition, and is quoted in the gallery guide as saying that his work is "about life and death and all that stuff". Well, one might ask, what art worth its salt isn't? Hirst's sheep is here, as well as a couple of his one-colour paintings with dead butterflies mired in the paint, and a vitrine that includes a desk, rather than a cow, sawn in half. It might be easy to view this show purely in terms of its mordant, sometimes alarming content, with Hirst as head bad-boy, but the best of "The British Art Show" - especially in film, video projection and photography - occupies a territory in which menace, beauty and humour, real life and fiction have an equal place.
Steve McQueen's beautiful, balletic film of black wrestlers, warily circling one another, explodes not into violence but ends instead in a tender, intimate embrace, the camera bringing us sweat-close to their naked bodies. It is a beguiling play on the viewers' expectations. In a second film, McQueen's bird's-eye shots of slowly gyrating hula-hoopers switch to a close-up of feet crossing a tightrope and to a woman pulsating in a sequined dress. Finally, with a switch of camera angle that leaves the viewer floored, a man looms above us on the screen, takes out his penis, waggles it once, then begins to urinate, filling the screen with bubbles, glistening droplets and spreading ripples.
Sam Taylor Wood's video Brontosaurus shows a naked man dancing alone in his living room. His frenetic jerking around has been slowed-down, and, instead of the blasting jungle techno track he's listening to, we hear the strains of a melancholic orchestral work. His buttocks quiver, he waves his skinny arms, his penis flops about and his face goes through some embarrassing contortions. He looks like a prat but there is something moving about the way the film homes in on his self-absorbed pleasure, his vulnerability and -ultimately - his sadness.
Some of these works have enormous resonance. Julie Roberts's tight, highly detailed paintings of medical equipment, straitjackets and old dentist's chairs, and Catherine Yass's back-lit, solarised colour photographs of vacant hospital corridors, arehypnotic apparitions of the unfathomable, resisting interpretation. Yass's photos, as much as they capture the outside world, invoke the super-lucid vision of an attack of paranoid psychosis. Douglas Gordon's footage of a First World War trauma victim falling, flopping and twitching helplessly on the floor, is similarly fraught. His projection of extraordinary footage of a masked woman in the grip of an hysterical fit, brings us up short against the pleasure we take in looking, why we look, and what we hope to gain or learn. We find ourselves in much the same position as the pair of sinister physicians who appear to be taking sadistic delight in her symptoms.
Like Gordon's presentation of pre-existing material, much of the best work here presents itself purely as documentation, albeit in a stylised form: Christine Borland's PortaCabin set up as an instructive Black Museum for trainee forensic officers; Gillian Wearing's vox pop photographs and videos; Bridget Smith's photographs of cinema screens with the curtains down, the empty cinema alive with the shimmering glow of the footlights. Georgina Starr has attempted to recreate the messy mental landscape of a 10-year-old's fertile imagination in her installation Visit To A Small Planet. Reconstructing moments from a half-remembered childhood incident, she comes in contact with the fantasies of adulthood, and finds that being a grown-up is just as encumbered and full of fantasy as the infancy she's left behind. A child's secret wishes - to communicate with animals, to read minds and to star in a musical - linger on long after the adult mind has decided such aspirations are untenable. The real and the fictional, it turns out, are not so easily disentangled.
n In galleries around Manchesterto 4 Feb, then on tour to Edinburgh and Cardiff