On a demure Radio 4 quiz show some years ago, I and other players were asked when we would like to have been born and choose a historical character. Among the Charlemagnes and Cleopatras my choice was dull but absolutely true - the year to be 1905 or so and the circumstances such that I could be a young man of independent means able to wander about Europe observing its descent into the Gotterdammerung that struck in 1939, the Hungary of Admiral Horthy, the Romania of the Iron Guard, the Germany of Berlin, Weimar and Nuremberg my bailiwicks. This was not a taste for luxury, but the indulgence of intense curiosity into the willynilliness with which the Continent, having destroyed its economy and ancien regime with one world war, within two decades plunged into another.

Many of those born a century ago went no further than Paris, which between the wars was an intellectual honeypot for American authors who could hardly write and English painters who failed the Royal Academy, with penniless Russian princelings for its gigolos and taxi­drivers. Thither I too last week was transported by a play so convincing in its atmosphere and fragmentary narratives that I expected my mother to appear at any - indeed, almost every - moment from the wings. A play? A plotless play, a seamless sequence of immaculate vignettes that conjured the Twenties into sparkling brittle life, no leaden tale with a beginning and an end, all knots neatly tied, but an ingenious kaleidoscope of subtle insights into the human predicaments of lust and longing, power, wealth and poverty.

I write, of course, not as a drama critic, indeed not even as a man who goes often to the theatre, but who, when he does, wants in some sense to be moved. And I was moved, for this play, Semi-Monde, is an elegy for the lost souls of a brief age long ago. Its writer, Noël Coward, born in 1899, wrote it in 1926, the year of the General Strike, putting himself and his contemporaries in the Ritz Bar (though it could as easily have been the Trocadero or the Cafe Royal in London) under a microscope, not as might an entomologist with moths pinned to a cork mat, but as living creatures that, though capable of escape, are constantly drawn to the flame. It is their singeing that we watch.

Exquisite period piece though it is in this production at the Lyric, Shaftesbury Avenue, alley-cat morality dressed by Worth and Schiaparelli, Semi-Monde is as apposite now as it was when Coward wrote it and himself suppressed it in an age when censorship in England would quite certainly have emasculated it. We have jettisoned the decorum and the manners, but the morality is much the same, the prejudices too. Plus Ca change.

Semi-Monde opens with Nichola McAuliffe as a chanteuse singing a song in which the one word "pleasure” sets the period and style with an extended middle consonant so accurately Twenties, so sensual, languid and luxurious that we know exactly what awaits us: McAuliffe, it must be said, knows how to sing and can project the softest note.

Semi-Monde’s music is an extraordinary support to the dialogue, a solitary piano conjuring the White Russian émigré with a phrase from Borodin, the communist with the Volga Boatmen, and, raising the spectre of Fascism with wisps of Wagner, encapsulates the two great transitional powers that were inexorably dividing and consuming Europe - then slips whimsically into Mad About The Boy. This is a serious play, astonishingly percipient of, rather than about our history, a play that tells us in the rapid flash of images how it was in the 1920s, how from the determined pursuit of Carnival came Tragedy.

Semi-Monde maintains throughout a diamond-cut period precision and sustains our pleasure and our pain.