As soon as you enter the Pompidou Centre's show "Los Angeles 1955-1985: the birth of an art capital", the mighty roar of the MGM lion assails your ears. But the noisy animal quickly begins to look lazy rather than macho. He is, after all, a pampered Hollywood celebrity, not a lord of the jungle. Indeed, after a while, the noise he emits in Jack Goldstein's looped film sounds more like a self-indulgent yawn.
Yet there is nothing dull about the Pompidou's epic survey, a sure-fire way to electrify your weekend in Paris this summer. Directly oppo-site the lion, LA's own glamorous image of LA is reinforced in spectacular style. Ed Ruscha's colossal 1962 painting shows the 20th Century Fox logo projected through the night sky in titanic orange capitals. Ruscha calls it, with cool irony, Large Trademark With Eight Spotlights, and the jumbo-sized canvas has a bold, eye-punching impact.
Ruscha is the master of Californian pop, and the man who convinced sceptics that LA art really counted. At a time when New York dominated attention as the centre of the western art world, he gave the sprawling west coast city an arresting visual identity.
However, the Paris exhibition is as concerned with the seamy underbelly of LA as it is with Hollywood gloss. No trace of Tinseltown alle-viates Edward Kienholz's sculpture The Illegal Operation, made in the same year as Ruscha's sleek panorama. An abject female torso slumps on a rusty wheelchair in Kienholz's festering tableau. Something has gone horribly wrong, and the bedpan beneath the seat is a mess of dirty forceps and broken syringes. In another nightmarish installation, Kienholz shows two monstrous fibreglass creatures lying in a bedroom so grimy and forlorn that it makes Tracey Emin's bed look sanitary. Kienholz gave this 1964 tour de force a marvellously sick title: While Visions of Sugar Plums Danced in Their Heads.
David Hockney, the Bradford-born prodigy who made LA his home, defined a more restful and sensuous side of Californian life. No nightmares disturb the slumber of his tanned and naked youth, stretched out in the sun beside a pool alive with eye-dazzling reflections. Hockney is celebrating his own escape from grey northern puritanism, to a fantasy city inhabited by affluent art collectors basking in exotic mansions.
Towards the end of the 1960s, Robert Irwin gave LA art a more ethereal dimension. In his room, immense circles of light float and interpenetrate, like planets dissolving in deep space. The young James Turrell goes even further, beguiling us with a glowing horizontal oblong called Raemar Blue (1968). The work is as wide as a cinema screen, yet devoid of Hollywood movie icons. Nothing is permitted to disrupt the seductive blaze of colour.
Ironically perhaps, LA art consistently refuses to be pinned down to a single, easily marketable identity. Turrell's smouldering minimalism was soon challenged by the subversive antics of conceptual and performance pioneers.
John Baldessari, the form-breaking postmodernist who taught at the newly opened California Institute of the Arts, knew how to deploy an understated yet irresistible strain of humour. In one grainy black-and-white video, Teaching a Plant the Alphabet, he patiently holds all 26 letters in front of his silent, illiterate student. Throughout this solemn yet hysterical ritual, the plant remains impervious.
Chris Burden, by contrast, set out to unnerve his audience in a series of shocking performance pieces. Not content with incarcerating himself in a locker for five days, he subsequently horrified onlookers by ordering a marksman to shoot him in the arm with a rifle. The resulting wound is documented in painful detail. Far from being cowed by this experience, Burden went on, in Dead Man (1972), to dump himself beneath a tarpaulin on a busy nocturnal LA freeway. Two years later, he underwent a crucifixion lying on the back of a VW Beetle. It must have been hugely disturbing to witness these macabre events, yet Burden's deadpan attitude is far removed from any hint of expressionist angst.
LA artists never lost their cool, even as they approached the 1980s with a flurry of unashamedly weird images. Jon Borofsky constructed a large robot-like figure, gesturing manically and uttering incomprehensible noises in front of a canvas. He called it Chattering Man With Abstract Painting, and the ensemble, from 1983, seems to suggest that an encounter with art can be a deeply unnerving experience. Madness never seems far away in this final section of the Pompidou show. Mike Kelley presents a bizarre assortment of objects used in seven of the performances he carried out in Los Angeles. Made from rubber, leather, silver foil and electric wiring, they are redolent of rituals where confinement and suffering have been inflicted on the participants.
Mercifully, Kelley's exhibit avoids the gut-wrenching nastiness of Paul McCarthy's video Sailor's Meat (1975), where the bewigged and garishly made-up artist indulges in a feast of activities involving glutinous meat and ketchup. I have always found that McCarthy's in-your-face nausea quickly deteriorates into tedium. But if we hurry past his gross-out vision of life, other artists offer more rewarding forms of neurosis.
Jeffrey Vallance presents a shamelessly eccentric tribute to Blinky, the Friendly Hen (1978). Mourning a frozen chicken he bought at Ralph's supermarket, Vallance places Blinky's corpse in an outrageously ornamental coffin and gives it a proper burial. (He would mark the tenth anni-versary of Blinky's funeral by exhuming her.)
It is little wonder that Ruscha decided to paint a picture of the Los Angeles County Museum on Fire (1965-68): perhaps it contained exhibits so wacky it spontaneously combusted. Executed in an oddly unemotional and painstaking style, it shows a catastrophic amount of smoke emerging from the building where the blaze began.
By the end of the show, I felt I understood why he also painted a sunset panorama of the Hollywood sign, seen from behind. The view must have been observed by an artist bent on escaping the city's craziness as he headed for the hills.
"Los Angeles 1955-1985: the birth of an art capital" is at the Pompidou Centre, 75004 Paris (www.centrepompidou.fr) until 17 July