ARTS / Factory to warehouse: 'When you think of it,' Andy Warhol said, 'department stores are kind of like museums.' Now he has a museum of his own: a dollars 12m warehouse conversion which opened last Monday in Pittsburgh, his home town. It's a fitting showcase for his repetitive genius

FOR SOME decades now, artists have been tending to work on a large scale. This means that their output doesn't get absorbed into private houses and apartments as the work of successful artists used to be. All the unwieldy pieces which have not been acquired by museums, or by private collectors whose habitations virtually are museums, stay on the artist's hands, hopefully awaiting posthumous consignment to a personal museum. This prompts the alarming thought that one-man museums are about to proliferate. The fear is that such a museum will have an awful lot of the artist's work, but very little of his best work.

The Andy Warhol Museum in Pittsburgh owns about 900 paintings and numerous sculptures, drawings, prints, photographs, films, videos and so on, and great piles of documentary material: it is claimed to be 'the most comprehensive single-artist museum in the United States, if not the world'. The initial selection (by its English curator, Mark Francis) allays fears that the quality is not going to match the quantity. Some aspects of the work are not very well represented, but by and large there are first-class examples of all periods, and some are not well-known pieces. Quite a number date from the second half of the 1970s, a period that was scarcely evident in the big retrospective at the Hayward Gallery, London, in 1989.

For example, on the top floor there's a room given over to the Shadows series, and in another room, a small group of pictures of torsos - single torsos which are variously male or female, frontal or dorsal, and one work which presents a row of five repeated profile views of the same torso.

Each of these canvases was achieved through the typical Warhol combination of silkscreening a photograph and putting on synthetic polymer paint. The theme of the torso is one of the great themes that the art of our millennium has retrieved from the art of ancient Greece and Rome. This fact is less significant here than the fact that the images are photographic. And all of Warhol's mature work is as if inspired by a revelation that

a modern painter could and should exploit the photograph, as Renaissance painters exploited classical antiquities. For the photograph has come to assume the credibility which the Renaissance found in Graeco-Roman images and forms, though hardly for the same reasons: those antiquities got their authority from

their beauty, photographs from their truth.

The art of ancient Greece and Rome had, furthermore, a certain moral authority: the artist who modelled his forms on its forms was imitating the relics of a golden age of human history. But the photograph, too, has a sort of moral authority. We say that the camera cannot lie, and this implies that it's a trustworthy, honourable instrument. We know that in fact there are ways in which the camera can lie, but we act as if we didn't believe that. The powers-that-be insist that the picture in our passport - a picture that's a matter of life and death - has to be a photograph (provoking David Hockney to protest that a drawing ought to be an equally acceptable portrait). And the powers-that-be know, as we all do, that passport photographs often look very unlike the person. But these are still treated as uniquely authentic documents, such is the prestige that adheres to the photograph.

Painters have been exploiting photography for well over a hundred years, borrowing forms from the work of professional photographers and also taking photographs of their own as an aid to painting. The resultant paintings have rarely disguised the fact, and some have stressed it - works by Balla and Bacon, for instance. Warhol went much further. He created an art which would be utterly meaningless to anyone who didn't realise that it was made from photographs and was about photographs.

But truthfulness or supposed truthfulness clearly didn't top the list of what fascinated Warhol about photographs. Indeed, he altogether overturned the idea that photography filled a need for truthful recording while antiquities filled a need for an ideal beauty. Warhol used photographs for beauty rather than for truth. The faces that appear most repeatedly in his work are those of Elizabeth Taylor, Marilyn Monroe, Jackie Kennedy, Elvis Presley and others of their ilk. He turned to photographs of stars, as the Renaissance turned to antiquities, to find images of gods. Elvis mostly appears full-length as a cowboy with drawn gun (a publicity still for the film Flaming Star). There are usually three or four of him in a row; but at the Warhol Museum there's a previously unknown version, Elvis (Eleven Times). Nobody knows whether Warhol actually intended to show a row of this length or to cut the number down. They pose side by side in a lake of silver paint, some standing out from it distinctly, others almost dissolved in it, the rest in various degrees of clarity. Repeated again and again in this silver setting, his glance ominous, his face and hair smoothly sculptured, his body lithe and springy and balletic, Elvis is a reincarnation of Apollo. When Lautrec made monuments to the stars of the day, it was apt that he drew them, because they were live performers and drawing is a live art. Warhol's photographic images of the stars reflected the fact that the world knew them largely through the photographic image.

Another attribute of the photograph that Warhol exploited brilliantly was ambiguity. The glorious thing about the camera is that it's brainless and doesn't organise what it records, doesn't clarify it or limit it. All the photographs of disasters that Warhol used - mostly car crashes - contain passages in which it's wonderfully unclear what is happening. Because the familiar forms have been smashed up, we can't fill in so as to conceptualise what we're looking at. The uncertainty gives rise in our minds to one phantasmagorical scene after another.

A magnificent little-known example is hanging in the Warhol Museum. Dating from 1963 and entitled 1947-White, it is a variant on the more familiar Suicide (Fallen Body) of that year, one of the works in which the photograph is repeated in a grid, with variations achieved through the silkscreening, consisting in Suicide of four rows of four images each. In 1947-White the grid is less regular, is somewhat telescoped in the second and third rows, and in the bottom row is telescoped enough for there to be five images. Down the centre of the image is a woman lying on her back, seen head downwards. The smashed forms of the automobile behind and around her give no clear sense of what has happened, but it looks as if she is lying cradled in a hammock, which gives her a poignant serenity. Only the title Suicide (Fallen Body) tells us that her comforting couch is the dented roof of the car on to which she has thrown herself. That knowledge does nothing to diminish the mystery of the work, which goes far beyond the question now answered. The light reflected from the twisted car creates flickering tongues of flame or water or flesh. In 1947-White the middle rows are very luminous and the bottom row very dark, and the overall effect is one of writhing forms, rising or falling, in an Apocalyptic scene that might be a Last Judgement by Tintoretto or El Greco.

Repetition is everywhere in Warhol. Even when the individual work doesn't present the same shot five or 11 or 17 times, even when the work presents a single photograph, we know that this is a repetition because photographs are sui generis repeatable, and even the Polaroids Warhol perpetually took of people could be multiplied through silk-screening. The repetitiveness bound up with photography could have been what attracted Warhol to it most of all. He made a fetish of repetition. Works of his that bypass photography are still a celebration of repetitiveness. The Brillo Boxes, for example, and the Heinz Boxes and Campbell's Boxes. All of these, by the way, are particularly well shown at the Warhol Museum: they are not arranged aesthetically, tastefully, as they were at the Hayward and the Royal Academy's Pop Art exhibition, but are piled up as if in a warehouse, bringing to mind Warhol's remark, 'When you think about it, department stores are kind of like museums'.

Perhaps his most perfect game of repetition was played in Silver Clouds, the crowd of helium-filled cushions of metallised plastic film. They looked very beautiful at the Hayward retrospective, clinging to the curves of the concrete staircase like Baroque putti up there adorning a column. But at the museum they are presented as they were when originally shown in 1966 at the Leo Castelli Gallery in New York - filling a smallish room in which they float up and down and around in response to electric fans and the heat emanating from people's bodies, moving at differing speeds, here huddling together, there bumping into one another, and into us. Their blindness is as appealing as their sameness. It is difficult not to see them as living creatures. They seem to have the vulnerability and will to live of maggots. Above all, I was told by a colleague brought up in Australia, they are like sheep. 'I think it would be terrific,' said Warhol, 'if everybody was alike.'

Warhol's love of repetition was also manifest in his life. 'I used to have the same lunch every day, for 20 years, I guess, the same thing over and over again.' The question is to what extent he simply had an addictive nature and echoed in his art his need to live obsessively, to what extent his faith in repetition was a conscious philosophy. The staggering size and variety of his creative output, and the readiness to delegate that this demanded, suggest a relaxed personality who could make his energy go a long way, not get knotted up in involvement with compulsive patterns. The love of repetition was tied up with a cult of standardisation which seems to have been more than a mere taste for experiencing the same thing over and over again.

Nan Rosenthal has even argued, in a remarkable lecture, 'Let us now praise famous men: Warhol as art director', that while he was at Carnegie Tech, Warhol was influenced by Bauhaus ideas about the virtues of standardisation, ideas which involved a rejection of the prejudice that hand-made artefacts were a priori morally superior to manufactured artefacts. The earnest tradition of the Bauhaus backed up Warhol's flip remark, 'The reason I'm painting this way is that I want to be a machine.'

So an old-fashioned modernist approval of standardisation tied in with a personal liking for popular culture. There is irony in this statement of Warhol's, but it's not unserious: 'What's great about this country is that America started the tradition where the richest consumers buy essentially the same things as the poorest. You can be watching TV and see Coca-Cola, and you can know that the President drinks Coke. Liz Taylor drinks Coke, and just think, you can drink Coke, too. A Coke is a Coke and no amount of money can get you a better Coke than the one the bum on the corner is drinking. All the Cokes are the same and all the Cokes are good. Liz Taylor knows it, the President knows it, the bum knows it, and you know it.'

At the same time, the love of mass culture was radically different from that of the masses. 'I could never stand to watch all the most popular action shows on TV, because they're essentially the same plots and the same shots and the same cuts over and over again. Apparently, most people love watching the same basic thing, as long as the details are different. But I'm just the opposite: if I'm going to sit and watch the same thing I saw the night before, I don't want it to be essentially the same - I want it to be exactly the same, because the more you look at the same exact thing, the more the meaning goes away, and the better and emptier you feel.' From Pop to Zen.

If there is any doubt that Warhol's art is ample or deep or interesting enough or likely to be enduring enough to keep a one-man museum alive, it has to be remembered that the museum is also going to house and show his output as a film-maker. (The museum, a handsome 1911 warehouse, has been admirably renovated by Richard Gluckman in ways that make it serve its purposes, rather than call attention to the architect.) I think that film is where Warhol's supreme achievement lies. Whatever his genius - and his shattering originality demands that word - his output as an artist is probably not of the calibre of that, among his contemporaries, of Jasper Johns or Cy Twombly or Robert Rauschenberg. In the far more competitive, and culturally more important, domain of the cinema, he seems to me to stand to the fore among his generation throughout the world, along with Godard and perhaps Pasolini and Oshima.

That peerless writer on cinema, David Thomson, places him in a still more select pantheon: 'Warhol's films do have the sort of stylistic minimalism and dislike of expressiveness to be found in Ozu, Hawks, Bergman, Dreyer, Rossellini, Godard and Renoir; the style, I would argue, that is most elevated in cinema . . . They shared Warhol's reluctance to urge meaning into the action through the ingenious placing of the camera. Like him, they tried to serve their actors.' Or, as Warhol put it: 'I only wanted to find great people and let them be themselves and talk about what they usually talked about and I'd film them for a certain length of time and that would be the movie . . . To play the poor little rich girl in the movie, Edie (Sedgwick) didn't need a script - if she'd needed a script, she wouldn't have been right for the part.'

One of the strengths of artists in all media in the first half of the 20th century came from a readiness to follow Mies van der Rohe's precept, 'less is more': they simplified and purified their forms, rid them of excrescences. One of the strengths of artists in all media in the second half of the 20th century has been that they seem to have believed that less intervention is more: they set things in motion and then let them alone, not trying to control them, but allowing them to take their course and their chances. Warhol was a perfect exemplar of that.

The Andy Warhol Museum: 117 Sandusky St, Pittsburgh, PA (0101 412 237 8338), open Wed- Sun. Pittsburgh is 390 miles from New York, and 250 miles from Washington DC.

(Photographs omitted)