This November, the largest, grandest and richest modern art museum in the world reopens after a two and a half year closure to allow for an architectural expansion expected to cost up to $858m. The project to reshape the Museum of Modern Art, located between 54th and 53rd street in midtown Manhattan, is pharaonic in scale. At the hands of Japanese architect Yoshio Taniguchi, it has become twice its former size. The revamped museum offers 50 per cent more gallery space (125,000 sq ft), an enlarged sculpture garden, a new lobby and a set of column-free exhibition spaces specifically designed to accommodate displays of ever vaster works of contemporary art.
Moma (while there are other Museums of Modern Art, this museum has long taken sole ownership of the acronym) possesses the most significant collection of its kind internationally: more than 100,000 paintings, sculptures, drawings, prints, photographs, design objects, architectural models and drawings; 14,000 films and 4m film stills; more than 200,000 books and periodicals. Moma's magnetic pull over the dreams of donors, curators, artists, dealers and visitors, even before this latest building bonanza, was unrivalled. For some, this alone is cause for suspicion: "Moma's aura is in direct proportion to its efficiency of manipulation," the architect Rem Koolhaas has said. For others, the verdict is less sinister: "Moma has long served as an American metonym of modern art, with the history of the one often charted in the other," the historian Hal Foster has written. Either way, because of the stakes involved, whatever Moma does has repercussions for galleries everywhere else. More than just a museum, it has become the crucible in which the idea of the modern has been formed.
Seventy-five years ago, when Moma was established by a few enthusiastic philanthropists on the 12th floor of the Heckscher building at 730 Fifth Avenue, the idea that the new could be as exciting as the old was itself radical. In 1929, most museum directors believed that the past - a place filled with gilded echoes of long-dead Mediterranean civilisations - was more important and beautiful than the present. Modernity itself was in its infancy. Van Alen's Chrysler building, that hypodermic shot into the future, was begun the previous year; the Empire State building was still just a dream; neon was tracing out the New York skyline for the first time.
That the museum's founders gave it the name the Museum of Modern Art, when it so easily could have been named after any of its major benefactors - the Rockefellers, for example - was a measure of their ambitions. Alfred Barr, Moma's first director, was aware of the Herculean task he faced: to create a museum that was populist in spirit, in which a single story could be told of the development of art from 1880 (the approximate date at which it was agreed that modern art first manifested itself) to the present, and on into the future. Perhaps the cleverest move was a decision to collect by medium - painting, drawing, photography, film, design objects - rather than by date. Instead of creating any one "department of contemporary art," this allowed curators of each area to focus on adding to its collections as they saw fit.
Moma's first exhibition in 1929 focused on Cézanne, Gauguin, Seurat and Van Gogh, a choice that sought to identify modern art's roots in post-impressionism. But establishing which artists, or which parts of their careers, stood on this or that side of the line (Cézanne was one of the trickier cases) preoccupied Barr and his team as they sought to placate the sensitivities of the Metropolitan Museum of Art, until then America's cultural acropolis. Barr's celebrated "torpedo" diagrams of 1933, in which he sketched out the ballooning evolution of post-impressionist, modern European, American and Latin American art, were an attempt to establish a new canon of art, relying on a Delphic sense of what was to come as well as a shrewd dissection of what had passed. Artistic progress was thus unwittingly designed in the shape of lethal weapons that, in less than a decade, would explode the old connections between Europe and America and reverse the cultural dominance of the former over the latter in the years following the second world war.
Barr's sketches took the form of a machine. New York is a city once eagerly defined and now haunted by dreams of a mechanised utopia, of progress delivered by mass production. As late as 1995, Philip Kasinitz in his book Metropolis: Centre and Symbol of Our Times could still envisage Manhattan streets as being synonymous with the structures of mass communication, capitalism and popular culture. "New York," Kasinitz confidently wrote, "dominates the conceptual and symbolic vocabulary with which we think of the modern city." But for Jean Baudrillard, writing in 1986, America, while being "the original version of modernity," was also "an achieved utopia, confronted with the problem of its duration and permanence." The challenge of remaining new - of maintaining its primacy as modernity's meta-city, the city celebrated in musicals, films and photographs as the world's greatest urban experiment - has bedevilled New York for at least the past 30 years. The truth is that New York is on its way to becoming another Venice, a museum trading on past glories.
To stay new is the single most important challenge faced by Moma today. "Modern art is still unfolding and its history is still being written," claims Glenn Lowry, the director of Moma since 1995. But how can a mus-eum of modern art, charged with the responsibilities of looking after increasingly precious works from the past, keep pace with the onward march of creative practice? (It is not as if midtown is an avant-garde quarter.) "It's unrelenting," Lowry continues. "You have to keep up with what is happening today and to be willing to go back to more historical moments and to identify what gaps there are and to pursue them with a relentless commitment."
This is a plate-spinning act that Barr would have understood. In 1939, Moma marked its tenth anniversary by moving from rented accommodation into its first purpose-built site at 11th West 53rd Street (now just one part of the current mammoth Moma complex). The building, designed by Philip L Goodwin and Edward Durell Stone, was a cool example of the new international style, self-consciously futuristic. But early on, Barr changed the temporary lighting fixtures and thin walls, which allowed for flexibility in the displays, into fixed units. He must have sensed that, at this formative stage, the desire to produce an authoritative history of art would be more powerful an impulse than the need for constant reinterpretation. The risk of fossilisation, meanwhile, was avoided by the accord Moma's authorities signed with the Metropolitan Museum of Art in 1949, which stated that the younger institution would transfer its masterworks of art aged 50 years and more to the older in exchange for acquisition funds to buy new art. It is a decision that Moma curators must have subsequently bewailed as they stood, for example, in front of Picasso's Woman in White of 1923, now in the Metropolitan. Reading the typed list of proposed works for transfer to the Metropolitan drawn up on 4th July 1947, you notice Barr's handwritten notes to the right, adding years, and sometimes decades, to the time periods masterpieces would be allowed to remain at Moma prior to transfer. Though Barr knew that the discarding of works enabled the museum to stay fresh, his reluctance to part with great works is palpable. Many collectors had specifically donated pieces to Moma, and it was Moma which took the risk on establishing artists' reputations. In 1953, the arrangement was terminated.
Thus Moma's love affair with architecture was born. With the decision to collect and not to discard, the only option was for the museum to grow. Since Goodwin and Stone's design, five further building campaigns have occurred. In 1949-51, Philip Johnson's seven-storey Grace Rainey Rogers annex, with its façade at 21 West 53rd St, was added (only to be demolished in 1979 to allow for the west wing); in 1952-53, the Abby Aldrich Rockefeller sculpture garden, also designed by Johnson, brought some welcome exterior space into the museum's ownership; in 1964, Johnson added a new east wing to the Goodwin and Stone building; in 1984, Cesar Pelli's new west wing added further space, including a massive skyscraper inserted in the middle of the site, in order to raise commercial revenues for the museum; all of which has culminated this year, with Yoshio Taniguchi's renovation and expansion. As the steel, concrete and glass has piled up, so the size of the museum's collections and visitors has increased: 64,000 objects in 1980, over 100,000 objects in 1995, and several times that amount now. Audience growth has also been remarkable - 900,000 a year to over 1.8m in less than a decade. British museum directors can only stand in awe at the achievements of Moma's board, the most powerful in the art world.
Moma's board has, over the years, included most of the major business names in America, although this most exclusive of clubs has become more international of late (the new Akio Morita media gallery, for example, was funded by the late chairman of Sony, whose widow is a board member). They do not use their wealth to hoard art treasures for themselves - think austerely dressed 17th-century Amsterdam burgomasters rather than corpulent papal scions. Moma stands as one of the major achievements of American philanthropy, its funding coming largely from private rather than corporate sources, and Lowry has duly seen more than $710m of the museum's $858m capital campaign goal raised already. Just as the Pantheon in Rome was funded in a public act of charity by Agrippa, whose name it still bears, so these benefactors expect their munificence to stand the test of time.
Yoshio Taniguchi was an intriguing choice of architect. Alth-ough he had been acclaimed for his sensitive, ethereal compositions for museums in his native Japan, winning the competition for Moma's redesign in 1997 was his first international commission. According to Taniguchi, his aim was to create an "environment for art" rather than a piece of signature architecture. The size of the renovation project required that it be treated as a case of urban planning. "As opposed to designing one thing of beauty, I design a museum within a city - a city within a city," Taniguchi says. In fact, his solution was strikingly simple: to define two different façades around the site that subtly emphasise rather than disguise the dual nature of the museum's site, which faces north to a smart residential area just south of Central Park and south to the swish commercial hubbub of midtown. North, along 54th Street, he has created a single unified façade of Zimbabwean black granite, aluminium, dark grey glass and clearer glass finely fritted in alternately clear and white lines. This creates the appearance of a fully integrated complex. South, along 53rd Street, he has preserved the Johnson, Goodwin, Stone and Pelli façades while adding one for the new gallery complex to their western side. In purely aesthetic terms, Pelli's tower seems a brash corporate gatecrasher to the museum's arty party. But rather than seeking to camouflage it, Taniguchi has instead articulated its northwest and northeast corners in black glass, making it a central axis point within the complex and offsetting the generally horizontal aspect of the museum's other buildings. From inside the complex, he gives new vistas of the trunk of the tower that he has clad in matte granite. This is a diplomatic and clever move - to clarify another architect's intervention while separating it visually from his own work. However, with the dominant use of black granite around the outside of the museum, he does something more than merely reference the monochrome discipline of Mies van der Rohe's nearby Seagram building. He also unintentionally casts a mournful veil around Moma as a whole.
More happily, Taniguchi has created multiple points of entry to the museum - a fashionable gesture, providing metaphors of social inclusion. That said, Goodwin and Stone's original building (its streetside canopy is now restored) was itself an innovation in this regard, dispensing with the traditional flight of steps, pillared and pedimented frontage, in favour of a building style that, with its street-level lobby, large glass elevation and unhierarchical entrance, underlined the democratic character of the institution. But for a museum, it is the interior that really counts. Here Taniguchi has pulled out all the stops. A new block of galleries in which the previous circulation - where visitors would enter galleries of older modern works before winding their way through to the contemporary galleries - has been reversed. Contemporary works are now encountered on the first gallery level in a massive space that has the advantage of being completely without columns. The engineering solution that allowed for this was ingenious: four temporary 22ft columns were inserted in the core of the space as the gallery block was being built. When the builders got to the seventh floor, they put in giant trusses that transferred the weight to the sides and then went back to remove the columns below.
Two conventional problems were solved by creating this column-free space. So much contemporary art just keeps on getting bigger and heavier (Richard Serra's Intersection II weighs more than most small ships). So on the second floor (the first gallery level), access for hefty art-moving equipment is easily available. It also solves a problem for the curators who, able to reorganise this most necessarily fluid part of the museum's narrative programme, can present any number of different interpretations as to the continuing debate about where art is or is not going.
The implications of this reversal of narrative circulation are considerable. Visitors are immediately thrust into a vision of the "now" - a baptism of fire, perhaps, but a neat way of getting contemporary people to meet contemporary art on equal terms. By shop-fronting the contemporary in this way, the museum can claim to have surmounted its age-old concern about how to stay new. The decision about the contemporary spaces was arrived at through constant discussions between the architects and the curators. It was "an obsessive relationship," Lowry says. "Taniguchi's vocabulary draws on international modernism but he inflects it with his own style. These rooms are meant to be restrained, but not neutral." The ambition was, he adds, "to ensure that we constantly surprise visitors. Regularity kills the experience. We wanted more nuance, a less linear sense of art history by encouraging serendipitous discoveries and juxtapositions."
The result is a mix of galleries in which some spaces have a fixed function in the overall exhibition narrative, while others would be more variable in use. But Lowry says that Taniguchi was asked not to distinguish such spaces rigidly. "Over time, a variable space may come to be a fixed conceptualised space and vice versa," he explains. It is a postmodern solution which allows Moma to pose questions about canon, ideology and narrative without losing sight of the overall plot. "The analogy of the museum as laboratory is an apt one," Lowry continues. "Just as with any scientific experiment, you never know how it's going to come out. But it enables us to zero in on an artist in greater detail, to explore a particular historical moment, to address issues on a thematic level, and to introduce works from other departments. We might have, for example, a cubist 'moment,' when paintings and sculptures meet photography and prints. We're just going to play this out, take a breath and then see how it might change in six months."
There is a monumental irony in this. Just as Moma reaches its greatest size and impact, so the notion of art history is itself imperilled. The choices made by Lowry and his team as to how their narratives are articulated - which work goes where and why; how will they start and end their displays of historic art movements - are bewildering in their possible outcomes and, indeed, possible errors.
A crucial aspect of this new arrangement is how the movement on from post-impressionism, that watershed moment at the turn of the 19th century, is managed. It used to be held that cubism, the moment of fracture in art when the reliance on one-point perspective was challenged by the proposition that multiple perspectives more accurately reflect our experience of the world, was the next logical step in the narrative sequence. Other moments like fauvism, futurism and surrealism served as important but subsidiary adjuncts. The new layout offers two exits from the post-impressionist gallery, one leading to cubism, where Picasso's Demoiselles d'Avignon is as resplendent as ever; the other to fauvism, the equal importance of which is now widely recognised. "This is the real novelty of the spaces we have created for ourselves - it allows for more complicated relationships," beams Lowry.
Attentive visitors, however, will notice the way Moma has now reopened the story of the modern. Instead of Rodin's St John the Baptist Preaching, which used to stand outside the galleries, pointing to Cézanne's The Bathers, Lowry has decided to start the collection with Signac's 1890 Portrait of Félix Feneon. This, he says, is "a great magical gesture that essentially raises the curtain on the very idea of modernity. It is Signac's greatest picture, though he's not the artist you'd usually pick." Dispensing with the Cézanne (Lowry claims it is a "rétardaire picture, still wrestling with Poussin") and highlighting instead Feneon - the Parisian critic, collector, impresario and anarchist - is a telling move. "It's about showmanship, the masses, about a fundamentally different moment," he continues. "It's almost the same date as The Bathers, but it's about the curtain coming up on popular culture, breaking through the screen of avant-garde art. It pinpoints the notion of celebrity and offers us references to Warhol later in the hang."
This, then, is how Moma has recast the history of modern art as seen from our times, with showmanship and celebrity culture the dominant thread. Each generation retells history its own way, but is this really where the march of progress has taken us? It risks appearing as just a repackaging of those features of modern art that conveniently mimic our current, transitory obsessions. But for Lowry, the story of modern art is not complete without the canonisation of Andy Warhol, the original media-savvy, celebrity-driven artist. "Of the giants of this period, he is the guy," says Lowry. "Pollock is already over."
Most art dealers and artists, meanwhile, will be focusing on what the contemporary galleries have to show, and this is where it gets hot. "We've never been able to show minimalism and post-minimalism together. They're really about a confrontation," says Lowry carefully. "You'll see Judd, Martin, Flavin and Andre as one generation of minimalists but then there's Lewitt, Whiteread and radically different artists like Beuys, Palermo and Nauman whose work moves in a very different direction. There's this pivotal moment in the mid-1970s, with lots of competing ideas and counter-sensibilities." Before the 1970s, the official line was that after the war New York had taken over from Paris as the centre of contemporary art, but since then suzerainty has shifted between America and Europe, with new centres opening up in the far east and Latin America. It is now the type of contemporary art, not where it is being made, that determines critical and commercial success. In this regard, Britain has recently proved an important hub. Moma's latest acquisition of Francis Bacon's Triptych (1991), for example, "allows us to look at figure painting in the 1980s in a very different way," says Lowry.
Yet with the lines between contemporary art, design, architecture, media and commerce increasingly blurred, the "contemporary" is a much trickier target to define than the "modern." With such a vast collection, one wonders what Moma would not collect. I noticed a helicopter - a crop-duster - hanging from a ceiling. Would the museum collect military hardware too? "Moma has always shied away from accumulating military weapons, be they tanks or handheld weapons," Lowry says. "The stealth bomber is pretty remarkable, though. I'd certainly make the argument that if we could acquire one it would be a mighty interesting object to have."
In terms of defining the contemporary, the Moma department with perhaps the most interesting future is that of film and media, the forms that now transfix people like no others. Warhol is a star here too - his screen test movies and three-minute films (played slowly at four and a half minutes) have been transferred by the department's director Mary Lea Bandy from video to DVD. "There's a great interest on the part of the traditional art world in embracing moving image artists," Bandy says. But the ubiquity of film and television presents her with a major problem: what should be collected? The founding premise of the department was, she says, "to collect those films produced by the inventors of the art of cinema, such as Thomas Edison. The decision was made pretty early on that the museum would collect self-consciously artistic cinema, documentary, animation - Walt Disney was an early supporter of the department - but that we would not collect three of the largest groups of films made annually: pornographic films, religious films or industrial films." This leaves Bandy with a rather vague principle, of collecting work that "tells you about the times you live in."
Asked which filmmaker she believes has been most important, Bandy doesn't hesitate: "Jean-Luc Godard. I think he's to the second half of the 20th century what Picasso was to the first half. He's influential and transformative, and his greatest work was the videos he started making in the late 1970s. They're these collage pieces where he's layering voice, music, natural sound, and text altogether. It's a different way of reading visual imagery."
So how might Moma's role as a showcase for film add to that of film festivals, where both new and retrospective material can be shown in its natural environment? The answer is that the film and media department is able to integrate its artefacts with the rest of Moma's collection in a way which highlights the syncretic relationship film has with other art forms. I am struck by the way Bandy uses Picasso's name on which to pediment that of Godard. It is the same process that took place in photography in its gradual transition from a documentary medium to a fine art. The new Morita media galleries at Moma give Bandy the chance to showcase early films, like Fernand Léger's Ballet Mécanique (1924), a 20-minute masterpiece of mechanical movement. Bandy is less than patient with museums such as Tate Modern which, she claims, don't give as much thought to displaying films as they do works of art.
Still, it is convenient that so many of the films in her collection are set in New York, or take the city as their subject. From King Kong (1933) to this year's The Day After Tomorrow, New York has been represented as not just the great modern city, but the place where modernity has been shaped. And it is significant that so many recent films have depicted the destruction of the city - with New York being blasted by aliens, stamped on by dinosaurs, submerged under water or buried in ice. It is as if they know the party is over, that the myth of modernism, the myth of New York, is now dying.
Since 9/11, of course, the fascination of the New York skyline has become the presence of the twin towers in earlier films, and their absence in recent ones. As a result, that skyline has itself acquired the character of a museum piece. The city has yet to be portrayed in a way that moves forward from loss, has yet to regain confidence of its place in the present. This is why it is so striking that Taniguchi has sheathed Moma in black granite, the same durable material used at Washington's Vietnam memorial. Is Moma, at its moment of greatest waxing, unconsciously prefiguring the end of so many dreams - modernism, the idea that art could programme the fragmented nature of contemporary life, the belief that free expression can exist unprotected in a dangerous world? Will this become the mausoleum of the modern, the multimillion-dollar enshrining of a set of treasures and ideals?
The choice of this mournful, immutable material is telling: "It is this 'finish' that repels our attention, that makes a monument invisible," writes James E Young in his book The Texture of Memory: Holocaust Memorials and Meaning. "It is as if a monument's life in the communal mind grows as hard and polished as its exterior form, its significance as fixed as its place in the landscape. For monuments at rest like this - in stasis - seem to present themselves as eternal parts of the landscape, as naturally arranged as nearby trees or rock formations." For us, the inheritors of the modern, the door is closing. New histories await us.
Moma reopens to the public on the 20th November.