It's one of those words – baroque. It's like "surreal", an art label that came unstuck from its original situation, and acquired a universal usefulness. Anything a bit weird can be surreal. Anything a bit complicated or overblown can be baroque. It's a perfectly handy everyday word. Just leave it there.
Take it any further, and things get... well, a little baroque. The likeness to surreal breaks down. Surrealism was originally a self-defined art movement. It coined its own name. It issued manifestos. It had accredited artists. Contemporaries talked about it.
The Baroque was a 17th-century movement that was unheard of at the time. The word wasn't introduced until the mid-18th century. Its derivation is obscure – possibly from the Portuguese word for an imperfect shell, or from a logical term for contrived reasoning.
As these things do, it started out as a term of abuse. It was deployed by neo-classical critics, a way of rejecting the frivolity and bombast that followed on the Renaissance. Later, it became more neutral, one of art history's big style categories. But with no "control" in contemporary usage, the Baroque can mean almost anything that a critic decides it means. The movement acquired its fixed art stars: the sculpture of Bernini, the painting of Rubens, the architecture of Borromini. But it also applies to music, drama, poetry and all kinds of design and decoration. There's Baroque politics (absolute monarchy) and Baroque religion (counter-reformation Catholicism). There's Baroque science and Baroque psychology.
Baroque can cover anything that was around in the 17th century and strikes you as exuberant, exorbitant, ornate, elaborate, theatrical, hysterical. If it's glittery and curly-wurly, if it's dynamic and dazzling, it qualifies. In her essay, "Baroque and Roll", Brigid Brophy boldly defined it by its embrace of direct contradictions! Whatever it means, it's a large, vague, shorthand name. Frankly, I try to avoid it – not that you always can.
Baroque 1620-1800: Style in the Age of Magnificence is the Victoria & Albert Museum's spring blockbuster. It opens this weekend. And even before going through the door, you can see that it's not going to narrow down the definition. Check that title: a movement generally set in the 17th century is extended through the whole of the following century, too.
What's more, the show takes the Baroque out of Europe and across the world. Colonisation took it to Peru and to Indonesia. It was the first global style. And the exhibits go beyond art and artefacts – there's every sort of luxury object, from an ornamental sled to an ornamental ostrich, an entire and huge Mexican altarpiece, and (on film) an authentic period firework display.
It does everything it can to imitate itself a Baroque spectacle. You proceed through galleries devoted to various places of display – the theatre, the public square, the church, the palace, the garden. Baroque music accompanies you.
The Baroque work, we're told, is focused upon a single effect. It always has its eye on the spectator. It wants to overwhelm you with a total work of art. We should feel at home, then; the Baroque near enough invented "the experience".
So I think you can see what you're in for. I've talked about the phenomenon before. It's a show that has one of these telltale words in its title. Magnificence. Majesty. Splendour. Grandeur. Triumph. Treasure. Golden. Civilisation. Epoch. Age. (In this case, it's got two of those words.) And the point of such exhibitions is that, over and above the value of the individual works, we are to be wowed with what they add up to. It's a power and glory show. A whole culture glares us in the face.
There's an obvious practical problem. The bigger the subject, the harder it is to exhibit it in a museum. But you won't find any churches in the V&A – somehow they couldn't be shifted and shipped. You won't find Tiepolo's great ceiling painting from the Würzburg residence. You won't find the Hall of Mirrors from Versailles, nor any theatres or throne rooms or parks. What you'll find instead are scale models and films and contemporary images recording such things.
As for the work of Bernini, essential to any view of the Baroque, what can you do? It is, where moveable, basically unborrowable. His masterpiece, the sculptural tableau The Ecstasy of St Theresa, is neither. It's represented here by a poor painting of it and a clay fragment of her delirious face, left over from the making process.
Personally, I think they should have got a decent full-size simulation of it constructed. Actually, there would already be one in the V&A's cast room if a taste for the Baroque had got going earlier, during the Victorian age, when these casts were taken. But nowadays conservation won't remotely permit the practice. You'd have to make it new. Film artists could do it.
Short of that, there's nothing to be done about it. It's impressive the amount they've managed to gather, yes. But what an exhibition sometimes gains in being able to show the real thing, it too often loses in not being able to show the real thing. It would be awful for the V&A to admit that a sumptuous coffee-table book would do as good or better a job, but it seems to me that it would. Or a sumptuous coffee-table TV series.
There's another problem – a problem of belief. In this show, you're witnessing a grand exercise in personification. The Baroque (we learn) invented opera. The Baroque also invented the dinner service and the easy chair. It gave us – how generously – many things that now seem fixtures of normal life. But it didn't. The Baroque was not a person to invent anything. These things got invented during the period in question – a period, remember, that lasted almost 200 years. Lots of things happened during that time.
Baroque: Style in the Age of Magnificence puts its faith in that old historical-philosophical fiction, the Spirit of the Age. It doesn't actually come out with it explicitly, but that is the desired effect. Everything it displays – from a filigree bellows to a bellying-out church façade – is, somehow or other, an expression of this movement of the world's mind.
Yes, of course there are fashions. There is always common ground to be found among contemporary products. But there are distinctions, too. With a group of works even by a single decent artist – by Bernini, say, or Rubens – you'd immediately start noticing differences as well as similarity. It's only with the mediocre that likeness dominates our view.
And there will also be flagrant exceptions to the broadest groupings. Vermeer's piercingly discrete paintings – are they Baroque? Or Racine's rigidly structured tragedies? Or Newton's laws of motion? They all fall bang in the middle of the age of the Baroque. How could they possibly have escaped its influence?
These age-style labels are blinkers on our vision. They exclude what doesn't fit. They impose sameness upon variety. They give us a little understanding, stressing the existence of connections, and restrict our understanding, by insisting that connection is the only important thing. Yet we love to be presented with a unified vision of culture. It makes things simpler.
We love power, too. And the deep moral of a show like this is a mystical power-worship. It suggests that the makers of art and history are not humans but mighty trans-human agencies – gods called Gothic, Baroque, Romanticism – that rule great stretches of time and hold the whole world in their hands.
You may find this sense of power empowering, just as (in a small way) you may find a show like this one empowering. You're presented with one big thing to admire and be amazed by. Fine – go along to the show and get moderately blasted. But then settle down and go back to using the word to mean a bit complicated and over-blown. It's all that it deserves.
Baroque 1620-1800: Style in the Age of Magnificence is at the V&A, London SW7, 4 April–19 July, every day, admission £11, with concessions (020-7942 2000; www.vam.ac.uk)