As a teenager I'd scoff at the unreality of the Hollywood musical, but now their numbers seem utterly delightful
We are now nearing the end of a run of days that, by my reckoning, are always the most enjoyable London can offer. They start around 22 December, when taxis, tubes and restaurants are at last empty of Christmas drunks, and end on 3 or 4 January, when work resumes. Every year during this interval, an older and easier kind of London asserts itself; also, an emptier one. The people for whom the city is mainly a work station go home to Lancashire and France. Commuters, if they bother to come in, return soberly with last-minute parcels on the teatime trains. Tourists are fewer, and easily avoided once you leave the axis that stretches from Harrods to St Paul's. On the buses, you notice more people like yourself: middle-aged, or past it, and often travelling with younger people with whom they seem on friendly terms. You realise these groups must be families – almost invisible at other times as a three-generational phenomena. Like you and yours, they are heading for a treat in a theatre, a cinema or a restaurant.
These are the days, in other words, that allow Londoners to rekindle a sense of civic belonging. The city seems more companionable, quieter, roomier. Perhaps it had a similar feel when I first came to live in London 40-odd years ago, in what turned out to be the last age of the bowler hat. The odd thing is that, in all the time since, hardly a month has gone by without some discussion of my leaving London, as if it were a temporary halt on the way to a more permanent destination. The last might be somewhere I'd never lived before (Dorset), or it might be somewhere I knew (Glasgow); but wherever it was, it was presumed to have some fetching, non-London qualities such as sincerity in human relationships and a view of some nicely shaped hills.
I think many couples in London have these discussions. The idea of leaving London somehow becomes necessary to the fact of living in it. Then – in my case – you sit on the top deck of a Number 4 bus as it crosses Waterloo Bridge one evening in late December and decide all this talk of leaving is (and has always been) nonsense. Most of your friends live here. Your children like it. Floodlit St Paul's sits prettily on the horizon. Just over the water, the Shard has nearly reached the height that will make it, for a few years, the tallest building in Europe – a vulgar ambition, but it suggests some confidence in the city's future. But more important than the scenery is where you are headed: the British Film Institute, formerly the National Film Theatre, which is just down the steps from the bus stop on the Southbank.
If I ever left London, the BFI would be the institution I would miss most. I realise this doesn't make much sense. The foremost cultural benefits of London living surely include the easy opportunities to see – in the flesh, as it were – a play, an opera, an orchestra, a Leonardo or the Elgin Marbles. Films, on the other hand, are designed to be infinitely reproducible and distributable. They can be watched anywhere, at home on DVD as well as in multiplexes parked on the edge of Scottish motorways. Release happens at the same time all over the country; London carries no special edge. Nor do the BFI's cinemas on the Southbank have any of the architectural distinction that can still sometimes be found in an old Odeon; the opposite, in fact. Squashed under Waterloo Bridge and between some of London's meanest concrete, they could disappear tomorrow and nobody other than film-goers would notice.
Nevertheless, a confession. Afternoons and evenings spent at the BFI have probably given me more pleasure in total than outings to theatres, museums and galleries. As a place of reliable entertainment, the theatre has become especially problematic. Perhaps we chose badly, but over the previous Christmas we went to a couple of favourably reviewed plays that were hard to like, or even to endure, leading on the way home to financial calculations (four tickets: £160, interval drinks: £20) and a promise never again to make the same mistake. The promise has been hard to keep this Christmas in a season that includes a revival of Michael Frayn's Noises Off and Graham Linehan's adaptation of The Ladykillers, both of them said to be excellent, but we managed to stave off temptation by booking seats for several BFI screenings, and in this way watched Les Enfants du Paradis and three MGM musicals – Meet Me in St Louis, The Bandwagon, Seven Brides for Seven Brothers – at ticket prices that, thanks to concessions, never rose above £28 for four.
I suppose this has to be counted as the cinematic equivalent of a sugar-rush, Les Enfants du Paradis being the only film among the four with anything other than the happiest of endings, but escapism is one of cinema's great contributions to modern life. As a teenager I'd scoff at the unreality of the Hollywood musical (wanting what instead? Doctor in the House? The Cruel Sea?), but now their numbers seem utterly delightful. What could be more charming than Under the Bamboo Tree as performed by Judy Garland and little Margaret O'Brien? Or wittier than the Triplets Song that suddenly erupts from nowhere in The Bandwagon? "We dress alike, we walk alike, we talk alike/ And what is more/ We hate each other very much … " To see that reproduced in a theatre would be wonderful, but it will never be seen in a theatre, because the stage musical in the film never existed, and Fred Astaire and Jack Buchanan are long since dead.
Still, you can see old films at home. You can probably watch a lot of The Bandwagon – certainly its significant moments – on YouTube. What the BFI provides is a big screen, an audience and a muted sense of occasion. Theatres sell glossy programmes thick with advertising; the BFI has free notes for each film on two sides of A4 that are thick with information. Other cinemas have trailers and Pearl & Dean, each vying noisily for a demographic of 14-year-old males; the BFI has neither of those – the curtains part, the film begins, nobody in the audience needs shushing (though sometimes the audience will applaud the film when it's over). Three BFI screens show films seven days a week. The choice is enormous. Later, you can drink or eat in a BFI bar or stroll round the second-hand bookstalls next to the Thames.
Something in the ethos reminds you of an earlier epoch: a restraint, even a high-mindedness that goes with words such as Third Programme and Arts Council of Great Britain. That's what comes of seeing the cinema as the 20th century's great art, worthy of state support, and it may not be unhelpful in the chastening decade to come. There will be Christmases more austere than the last, and there the BFI will be with its cheap seats and good films, helping to make London a worthwhile city to stay in. During the quiet of the past fortnight, it became my favourite place.