How London took over the art world and brought out the aesthete in the masses

Whether you're buying it, selling it or producing it - or just one of the thousands queueing up to visit the new Tate Modern - there is now only one place to be

Going to a museum was once a rather intimidating and rarefied experience attractive only to a small, educated élite. Today it has become truly a mass pastime. The museum has been called the cathedral of our age, but this kind of analogy no longer does justice to the heady mix of experiences available within the walls of such institutions.

Going to a museum was once a rather intimidating and rarefied experience attractive only to a small, educated élite. Today it has become truly a mass pastime. The museum has been called the cathedral of our age, but this kind of analogy no longer does justice to the heady mix of experiences available within the walls of such institutions.

It is now possible to shop (on a fairly broad front), eat (snacks and cordon bleu), drink (soft or alcoholic), form a liaison (sexual or platonic), get better educated (at any age), or just plain lounge around, while, of course, also browsing the art that adorns wall and floor.

And now in Tate Modern London has a world-class museum of modern art which is attracting an average of 20,000 visitors a day. Both shop and restaurants are packed.

London, like all major cities, is full of museums and public galleries, and all of them have been subtly or not so subtly metamorphosing into stylish emporia of the culture industry.

Dulwich Picture Gallery has recently reopened having had Sir John Soane's stately edifice (the first public gallery in England) complemented by Rick Mather's cool, glassy, extension, the principal function of which seems to be to provide the gallery with the now statutory café.

Next in line for a face-lift has been the traditionally rather stuffy Wallace Collection, which opened its modernising "Centenary Project" last Thursday. The National Portrait Gallery's new Ondaatje Extension, for its part, boasts a restaurant with one of the best views in central London.

The contemporary public gallery also caters for a whole range of other less immediately obvious needs. For some time, places such as the Royal Academy have been renting out their rooms for corporate functions.

It makes excellent economic sense. Galleries tend to be open only in the day time (although this, too, is changing, with Tate Modern open until 10pm on Friday and Saturday, and the Royal Academy open 24 hours during some of its blockbusters), so the empty spaces can transform themselves into impressive backdrops for various social functions.

For their part, sponsors of exhibitions, such as the accountancy firm Ernst & Young, take full advantage of their relationship with the Tate Gallery in order to host lavish dinners - complete with string quartets and specially tailored guided tours.

Another important aspect of today's gallery is the education programme. This will often span all ages, from kindergarten to University of the Third Age.

More and more, places like Tate Modern, the Victoria and Albert Museum, and the National Gallery are taking over the role of traditional educational institutions, running courses, hosting lectures and facilitating visits from schools eager to fulfil their national curriculum requirements.

Such diverse roles suggest to some that the public gallery is a quasi-utopian space within which what we hope are the best features of our society can be nurtured.

The art plays only one part in this more general process, acting as a focal point - even perhaps a pretext - for the bringing together of benevolent social forces. To less optimistic critics, our public galleries seem merely updated versions of the "bread and circuses" that once kept the Roman mob so happily pacified.