One reason for the play seldom being staged is its explicit rootedness in pre-revolutionary Paris; another is the fact that its hero is a mouthpiece for its author. When Figaro delivers a tirade against the "republic of letters" - "insects, flies, gnats, midges, the whole swarm of parasites" attaching themselves to the skin of the true man of letters - the person speaking is Pierre Augustin Caron de Beaumarchais himself.
And when we read Lee Hall's programme note for his new version of this play, there is a definite echo: "The braying asses in Tatler, who are so super-annuated that they have no need for anything else, and the lumpen masses clogged full of carbohydrate - swilling down the sweet, sickly tosh and thankful for the privilege - seem to be in consort to undermine whatever was valuable in our cultural life."
In the land of "reality" television, Hall continues, "the toffs and the slobs seem to be determined to peddle the pernicious lie that beneath their different accents we are all the same in our anodyne, depoliticised, touchy-feeliness. Figaro is the man caught drowning in the sewer of nutrition-free culture."
To find out how this 21st-century playwright made his 217-year leap, I meet him in his Camden abode, where the books don't so much furnish the rooms as fill them. On the desk is a long row of tomes about the Battle of Britain, of which more later, and one senses the financial ease that having written the screenplay of Billy Elliot (and its proliferating stage adaptations in Canada, Australia and Japan) must have brought. But Lee Hall could not be more sharply focused as he answers my question.
"I'd never seen the play," he says of Beaumarchais's Barber. "And although The Marriage of Figaro is the one that supposedly helped to foment revolution in France - its radicalism is obvious - it seemed to me both more mysterious, and more interesting, that The Barber had also created a stir." The problem, when he and the director Julian Webber read it, was its intermittent impenetrability. "But once we started to unpick it, we found something we hadn't at first seen. And the Bristol Old Vic invited us to have a go, to put our theory into practice, and to try to present the spirit of the play as it would have come across to a contemporary audience."
Like other 18th-century plays dealing in the stock characters of the lover, the ingénue and her old gaoler, this one, says Hall, was more about power than love. "It's about the role of the patriarch, and about what servitude meant then - as it has not meant since the French Revolution. I wondered how we could recreate that sense of imperilment that the other characters felt, which seems so remote to us now." For, in Western culture at least, patriarchs don't have that degree of control over other people's lives. "It was an almost academic puzzle, to work out how you could make it feel as it must have done at the time."
Hall found his solution to that puzzle in a world that is quite familiar to many television-watching Britons. His patriarch is an East End gangster who has retired to a villa on the Costa Brava. "And if Bartolo becomes this Ray Winstone character, we can understand the level of threat he exudes. Then all the relationships spring into contemporary relief. Rosine is a dancer whom Bartolo has met in a club, and he has installed her in his gilded cage - a villa that, for tax purposes, he calls a hotel - and he's trying to marry her."
Hall's Count Almaviva is "one of those guys you see at the back of Tatler at the 'party of the month'", and his Figaro is a failed London playwright who has gone to Spain to write his next work, but who, like Beaumarchais's servant, ends up as factotum to Bartolo.
In Rossini's opera, says Hall, Figaro is supremely confident, but the play is suffused with his anger, which goes much deeper than his contempt for the standards of the boulevard theatre of his day. "He despises the cultural attitudes of those in power, and, two centuries on, you often get the same complaint from educated commentators. Our Figaro is working class, he's probably been to a red-brick university, he's pulled himself up by his bootstraps, so this was a chance to have a crack at the dumbing-down of culture.
"Rosine's big interest is Andrew Lloyd Webber musicals [indeed, Hall's show is enhanced, just as Beaumarchais's play was, with new music and songs], the count is cultureless, and Bartolo hates culture. Figaro is alone in his love of literature. When the plot is fuelled by his anger, that mechanical stuff about secret letters and people popping in and out of doors and windows becomes less important. But the whole thing must work like a fantastic confection - if it doesn't, it's nothing at all."
Coming from Billy Elliot's creator, this last statement sounds like a concession, because that rags-to-Royal-Opera-House saga was, as Hall admits, "a fantasy autobiography". For Hall, who was born in Newcastle in 1966, the biggest event in his adolescence was the miners' strike: "It made a whole generation very aware of class politics, and it was hard not to feel that your whole region was under assault. The shipyards, which traditionally took half of the kids before they did CSEs or O-levels, stopped doing it the year I was 15. That was a marker for the future my generation faced. Unemployment as a career was a real prospect."
Hall's escape into the literary life via Cambridge University was very much in the style of Beaumarchais's Figaro. And that line of Battle of Britain books on his desk indicates yet another variant on the story. He has just finished the first draft of his screenplay for a film that, as with Billy Elliot, Stephen Daldry will direct, provisionally entitled "The Many and the Few", which focuses on that turning-point in British social history when the RAF realised that they had to double the number of their pilots, and that they could no longer depend on what Eton and Balliol sent them.
"There were a lot of Billy Elliots who wanted to get out of the mines and join the RAF. My story is about a squad where the mine-owner's son ends up in the same squad as one of the pit boys, with the inevitable culture clash. The characters are fictional, but the situation actually happened. The story is as much about the battle on the ground as the one in the air." Billy's reincarnations, it seems, can go on for ever.
Meanwhile, Hall is revelling in his role as a humble adapter. "Adapting someone else's play allows me to get inside the head of another playwright, and to have a conversation, which is reassuring for someone who works alone a lot. And there's no adversarial relationship between you and the director and cast, as there can be if it's your own play that you're trying to protect. Here, we're all round the table together, trying to make it work."
'The Barber of Seville', Bristol Old Vic (0117-987 7877), tomorrow to 11 MarchReuse content