Tate Britain's triumphant new hang

Over the past few months, Tate Britain has been undergoing slow but highly significant changes. Two long corridors of rooms – to the left and right of the Duveen Galleries – have been entirely refurbished and re-hung. And this week, with the opening of the south-east quadrant – the galleries that house works from 1930 to the present day (the date of each room is written in gold, on the floor) – the job will be complete.

The story of the development of British art from 1540 onwards will be told in its entirety, chronologically hung, and with more female painters on show than ever before. And there is one more bonus too. In the adjacent Clore Gallery, which principally houses the Turner collection, an upstairs room is now devoted to a permanent display of some of the greatest of the Tate's holdings of works by William Blake, Britain's greatest painter. Look out for the shrieking blue carpet.

Why hang works chronologically though? Isn't that what used to happen in former days at this institution? In recent years, the chronological hang has often been superseded by the themed gallery approach – Tate Modern went down this road. Theming can be a cunning trick, very useful for disguising the fact that there are huge gaps in the collection – as there were at Tate Modern when it first opened. Over at Tate Britain, chronology makes a good deal of sense. In a gallery devoted to the art of these islands, we have a yearning to see the whole story unfold, to make sense of its development.

Yet the chronological hang has its pitfalls too. There is what we can choose to call loose chronology and tight chronology. Loose chronology might bunch artists together by category – Elizabethans, Victorians, Edwardians, for example, or by some of the various "isms" created by professional art historians: Vorticism, Surrealism, Minimalism. Art professionals create structures. They teach us how to read the story of art. Regrettably, they also seem to suggest that there is a single story, their own, and that it is the correct one.

There are other problems too. When a gallery has been open for many years, favourites emerge, canonical works that must remain on display because the general public identifies the gallery with those works, and would be mightily disappointed not to see them there. Millais' Ophelia, for example. Loose chronologically, in short, can lead to dullness and predictability. We go to a museum because we know what we are going to find there. It is a form of cultural reassurance, akin to a well- padded leather armchair.

But a great museum should be more than that – and this is the problem that Tate Britain has chosen to tackle head-on. And it has done so by defining chronology in a slightly different way. Let us call this new approach tight chronology. How does it work?

The curators have been encouraged to look at the Tate's vast holdings year by year, with a plodding degree of thoroughness, in order to spot the unusual. Those many unusuals have now been deftly inserted into the story of British art. New names interrupt the flow. What is more, paintings made at about the same time – they might be separated by just a year or two – have, generally speaking, been hung close to each other so that we can see for ourselves quite how much obfuscation has gone on in the past, how many lies or half-truths the tellers of art's tale have been peddling.

Here is just one example. We find, to our surprise, that a work which we might have casually described as Victorian in impulse and style, was painted within months of one we would surely have pigeon-holed as Modernist. Sometimes there are several works on display by the same artist – but they are seldom displayed together in the same room. This hang is all about art's unpredictable ebb and flow, not art's stasis. Various works by Sickert, for example, appear in different galleries – a fairly customary townscape of Dieppe shows up in the 1890s gallery. He turns up again in the 1930s, the first of the suite of galleries in the south-east quadrant which go on display this week. By the 1930s he has changed utterly as a painter. His paintings are now based on photographic imagery – a tactic which Pop Art is wrongly said to have pioneered in the 1960s.

Because we are often accustomed to seeing works by the same artist together, gathered up into some great, posthumous retrospective (think of Lucian Freud's recent portraits' show at the National Portrait gallery), we are used to thinking about an artist's works in terms of each other. They grow out of themselves. They seem not to be emerging from the wider world of society or history at all. This hang corrects that purblind view time and again. In the gallery devoted to the 1940s, a work by Lucian Freud of a girl holding a kitten hangs next to one by Lowry of a relatively normal-looking house. We are troubled by the fact that in the usual scheme of loose art chat, Freud is somehow slightly above Lowry culturally speaking. Is high not rubbing shoulders with low in this instance then? All to the good. But what of this subject matter?

This strange, boggle-eyed girl with her strange boggle-eyed cat has often been spoken of as if it were some manifestation of the surrealist impulse – Freud was prone to that in the 1940s. When we look across at Lowry, our thinking changes. She becomes, in the clothes she is wearing, and in the company of that kitten, a small and local manifestation of 1940s domesticity who might just have lived in a house such as this one. Art history has changed in the blink of an eye.

The most dramatic change here occurs here when we shift across from the left-hand enfilade of corridors (which end with 1910) to the south-east quadrant, and enter that first new room, devoted to the art of 1930s. The presentation of the earlier centuries is fairly sober-suited because the art itself is consistently of a certain regular shape and size. When art comes to birth in the third decade of the 20th century, a great howl goes up. Sculptures shoot up totemically. Paintings posture in unusual sizes. So these new, later rooms, from first to last, are marvels of creative inconsistencies – works cluster on the walls in whispering groups. Paintings are hung at different heights on the wall. The rhythms are more excitable.

A mighty stone totemic Epstein stands in the middle of the floor, the likes of which we have surely not seen here before. Why? Because the floors could not take the weight. Now, newly strengthened, they are ready to brace themselves for everything that artists have had the gall to throw at them in the joyous near-anarchy of the later decades of the 20th century – and on. This mighty, partial survey halts, somewhat unwillingly, in 2013. There was no further to go.

In short, it's a curatorial triumph.

Walk through British Art, Tate Britain, London SW1 (020 7887 8888)