HISTORY YOU CAN LIVE INSIDE by Emma Darwin

A few weeks ago, my daughter's school Chamber Choir was singing Evensong in Southwark Cathedral, so I went along to listen. Many years ago, when I first crossed the Thames to live South of the River (which as all Londoners know is slightly more drastic than crossing the Channel to live permanently in France), in the daytime Bankside was busy with suits, doctors, and wholesale cabbages. But outside the working week it was Tumbleweed Town: anyone who could fled to the salubrious suburbs, and those few who couldn't had nothing to tempt them out of their grim blocks of flats.

Now the council blocks have been done up, there are university halls of residence, lofts and flats and family houses for urban living, there's Borough Market, the Globe, the Golden Hinde, the London Assembly, at least ten branches of Prêt à Manger, and you can walk along the Thames Path, from Deptford on your bank and St Katherine's Dock on the other, to Lambeth Palace and the Houses of Parliament. It's full of people living and working and drinking and talking. In becoming more modern, Southwark has become more ancient: it's once again the mirror-image of the city across the tide that gave birth to it.

Southwark Cathedral wasn't built as a cathedral, but as a church: St Mary Overey (as in, Over the Thames). So although it's a fine bit of Early English Gothic it's not particularly large or complex. But it still has that unity in difference which is the great joy of mediaeval architure: the pointed Gothic arches don't come just in large and small, but can stretch broad or high, vaulting above your head, or stooping to make a canopy over a baby's little tomb. Some of the columns are like bundles of saplings, others are great, ribbed tree-trunks; you walk through puddles of colours where the light from the stained glass windows splashes down as regularly as a wave.

There was a hymn, all solid, Anglican harmony, and then the Responsory: call-and-answer with the choir. And then the choir sang alone, weaving in and out of each other as pitched and patterned by Orlando Gibbons, and I remembered Peter Wimsey, in Dorothy L. Sayers' Gaudy Night, saying to his Harriet, "Anyone can have the harmony, if they'll leave us the counterpoint".

As one of Gibbons' contemporaries nearly wrote: Licence my roving notes and let them go / before, behind, between, above, below... But I couldn't - for good manners' sake - rove on foot during the service, thought I've done so in many other churches. So I sat still, and allowed my mind's eye to rove instead, imagining how as you walk and look the clusters of saplings in the different aisles set to partners and then pass on, the ribs like branches stretching out to join those of another tree overhead; triplets of windows dancing between bigger trunks; the arch that opens to a whole new chapel of variations; the path that leads you on, curls you round the back of the altar and brings you to the centre again, under the still, pendulum point of the crossing.

They say that architecture is frozen music. In which case, I thought, gazing up the column by my shoulder to where it sprang up and out into the vault, music is surely liquid architecture. What I'm sitting in - what those nameless medieval masons built - is a fugue in stone; a fugue that you can live inside. And perhaps a piece of music is therefore a building that sings.

So where does that leave the reader and writer of fiction? Like music, writing can only exist for the reader in time but, unlike music, it can only sing one note at once. The Donne (mis)quotation suggests that poets may be closer to music: their words have explicit patterning, repetition and sound. But fiction does have architecture: a novel has pace, scale and proportion, as I found when I started thinking about writing a novel as building a bridge. Ian McEwan says the first thing he knows about a new novel is "the maths", by which, as Pythgoras and Stravinsky would have agreed, he also means "the music". In fiction we can play as we choose with echoes and repetitions of ideas and images, as well as with sounds, and build them into something which you can live inside: the world of the novel not just in the sense of setting and characters, but a structure of sound and rhythm and image.

And historical fiction? Well, there's your answer: Bankside. Many historical novels take the reader to live in the year and moment of the action: - steam trains screeching and puffing above Dickens' head as he tries to rescue a six year old prostitute; two monks turned out of their priory as Henry VIII's men pull the lead off the roof; families emerging from the Tube station air raid shelters to see if their homes are still standing.

Other historical novels are also novels about history. The Golden Hinde is a replica of Francis Drake's ship that he sailed round the world, and there are modern American schoolchildren clambering about on it, snapping each other on their mobiles. But in the 1970s it was moored across the river, and my sister was on it - only because the Tower queues were too long - when the IRA bombed the Tower, killing one and injuring forty people. The Golden Hinde is a world you can enter and live in, a world at once Now, and many Thens, a world built of ribs and beams: wood, tarred and caulked to sail as well as it did five hundred years ago, dancing over the waves with the wind singing in the rigging. The replica embodies the history that it hasn't actually seen but also what it has seen, as novels about history do: a historical novel is history you can live inside.