THEATRE / Warm glow of Fanny by spotlight: A Busy Day - King's Head; The Seagull - Olivier; A Collier's Friday Night - Hampstead; The Schoolmistress - Chichester

ONE MISSING face among the crowd of 18th-century 'female wits' that hit the stage with the rediscovery of Aphra Behn and co was that of Fanny Burney - once best-selling novelist, darling of Dr Johnson, and reluctant Keeper of the Robes to Queen Charlotte.

Ever since the lovely show that Karin Fernald assembled from her diary in the 1980s, I have nourished theatrical hopes for this amazing woman. They are fulfilled in Burney's A Busy Day, an uproarious and warm-hearted comedy that lay forgotten for nearly 200 years before being unearthed by the Bristol Show of Strength Company last year. Alan Coveney, who discovered the text in a remainder bookshop and staged the Bristol premiere, now directs a cracking London production.

The title, with its offhand reference to the Aristotelian unities, is a clue to the play's appeal. Sophocles' Oedipus has a busy day; likewise Racine's Andromaque. Burney takes a tragic convention and turns it to fun (anticipating Goldsmith's Mistakes of a Night). She knows all about the rules of art and polite society, then throws them away and grabs you by the collar to tell a good story. Being Georgian England, it is decorous and bang-up-to-the-minute; the story of two lovers who meet in the East Indies and return to London, only to be driven apart by their respectively aristocratic and merchant families.

The lovers, Cleveland and Eliza, are an insipidly idealised pair. Nor is Burney up to much as a technician. She has difficulty in getting people off stage, and is apt to leave those who are on hanging around with nothing to do. But these mechanical quibbles are nothing to her comic energy, her gift for satiric portraiture, and the fact that the play has one strongly felt idea to declare: that merit has nothing to do with class.

The intrigue involves three groups: the blue-blooded Tylneys, the nouveau riche Watts clan, and a trio of privileged youngsters on the sexual make. For Burney, there is little to pick between them. The affected hauteur of Lady Tylney (Helen Weir) meets its match in the grasping vulgarity of the Watts ladies, while the rapacity of the boys is nothing to the husband-hunting coquetry of the filthy-rich Miss Percival.

At first they seem a vigorously one-dimensional crew, made simply to be knocked down. Then Burney begins to show her power as a comic artist. The blustering old Mr Watts (Geoffrey Collins) is revealed as a victim, obsessively lamenting his retirement from business to become a plaything of his mercilessly shopping womenfolk. The predatory Lord John (Brendan Hooper) turns out to be an illiterate, helplessly dependent on his sparkish crony (Ian Kelly) for ways to get through the day. What you learn is seldom to their credit, but as their foibles belong to the world of experience rather than to theatrical contrivance, you become increasingly fond of the people imprisoned inside the attitudes. The star turn in this department is Juliette Grassby's Miss Percival, a caricature of strict maidenly decorum, containing a fizzingly sexy girl who cannot keep anything to herself. The most artificial character is also the most natural. An eye-opener and a treat.

Besides allowing Dame Judi Dench to add another trophy to her collection of Chekhov leads, John Caird's production of The Seagull has the pretext of restoring a picture frame to the open stage; or, rather, four picture frames, which descend one by one on John Gunter's lakeside perspective, so that by the end you are looking through the accumulated settings of the whole play. The apparent aim of this romantically cumbersome design, supported by Dominic Muldowney's wistful valses oubliees, is to break the embargo on Chekhovian 'atmosphere'. The effect is contradicted once the opening image of the ghostly company drifting under moonlit birch trees gives way to the play itself, performed with full egoistic drive in a colloquially muscular version by Pam Gems.

The biggest single surprise is Norman Rodway's Sorin: not a defeated self-mocker, but a man getting in all the hugs, authoritarian tantrums and sardonic monologues he can, and going down - smoker's cough splendidly intact - still fighting. He presents a total contrast to Edward Petherbridge's listlessly elegant Dorn; and, indeed, to Alan Cox's youthfully nondescript Konstantin. Add to them Bill Nighy's passively bewildered Trigorin and the point emerges that it is the women who dominate this show: Anna Calder-Marshall and Rachel Power, as the frustrated mother and daughter, dancing to Kostya's playing in the next room; Helen McCrory's extrovert Nina, who brings the power of a whirlwind to the emotional confusions of the last act. And, of course, Dench. A moody monstre theatrale on arrival, she then blossoms into all the voluptuous complexities of the role, turning even the bandaging of her son's head into a show-stopping routine and hauling the defecting Trigorin to the floor for an act of masterful, crotch-fixated possession, while smothering him with literary flattery. Hilarious, terrifying, and heart-breaking.

Nothing much happens in D H Lawrence's first play, A Collier's Friday Night. Neighbours pop in and out; pit-grimed husband slams in for usual tea-time row, student son is so busy showing off his French to a girlfriend that they let the bread burn in the oven. That's about it; but what truth to the speech and manners of the time and place, and to the particular tensions of this household, where books have split family affection into guilt, emotional blackmail and

immovable contempt. Playwrights down to Dennis Potter have been living off this play ever since. It shows what naturalism is for. It creates theatre straight from the raw material and contains not a single false note. Barbara Jefford as the tight-lipped mother and Edward Peel as her ogreishly demoralised spouse are the principals in John Dove's excellent revival. But for a real slice of spontaneous life, look out for Sophie Stanton as the teasing neighbour.

The only problem with Pinero's farce The Schoolmistress is that it is hard to believe in the school, or in Patricia Routledge as its head. Once the girls get launched with a party of naval mashers and the place goes up in smoke to the popping of champagne corks, you can swallow everything; likewise, Miss Routledge's gold-booted return as Constance Delaporte, star of the comic opera. Getting steadily funnier after its staid preliminaries, Matthew Francis's production finally goes through the roof.

'A Busy Day', King's Head, 071-226 1916. 'The Seagull', Olivier, 071-928 2252. 'A Collier's Friday Night', Hampstead, 071-722 9301. 'The Schoolmistress', Chichester, 0243 781312.

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