All I remember of Field is a radio version of his golfing sketch, with the line, 'When I say slowly back, I don't mean slowly back; I mean - slowly back]', which was spoken not by the butter-fingered Field but his enraged instructor. For those who saw Field during his lifetime, What a Performance may stir happy memories. Others may be left wondering what all the fuss was about. Some of the old sketches are fun: particularly 'The Wide-Mouthed Frog', in which Suchet works up a fine pantomime bestiary while also making spontaneous contact with his house. 'What's wrong with my crocodile? How would you do a crocodile then?' Whether or not those are Sid Field's own words, when Suchet speaks them he becomes a comedian. Elsewhere, however painstakingly he reproduces Field's repertoire of twitches, trips, drunken staggers and camp pirouettes, he is an actor playing a comedian. It holds the attention; magic it is not.
What neither script nor actor delivers is any link between Field the exuberant performer and Field in real life, the invertebrate plaything of grasping managers and dominating women. In any case, given the dreamy style of Roger Redfarn's production, there is no visible boundary between fact and biographical licence. Did Field's father really like having his tea poured from a great height while hiding under the kitchen table? Did his mother actually propel the 12-year-old future alcoholic into the Royal Kino Juveniles' chorus line by tanking him up on Scotch?
With a facial mask switching from the severity of Olivier to the roguishness of Liberace, Suchet presents two unrelated characters who briefly coalesce on the occasion of Field's long- delayed West End debut. 'Overnight success,' he exclaims in sardonic triumph, 'after 26 years.' The treadmill of touring, with the benighted sessions on Crewe station, is shiveringly evoked. Anyone interested in that topic, by the way, should buy a copy of I'm Here I Think, Where are You? (Nick Hern Books, pounds 14.99), a gorgeous selection of Timothy West's letters to Prunella Scales, covering every aspect of touring, including the treatment of demon landladies (two kippers screwed inside the parlour sofa and left to mature).
The problem with Frederick Lonsdale's On Approval is not the plot - in which a pair of 1920s Mayfair lions test out their would-be marriage partners with a month in the wilds of Scotland - but the characters. How can the sensible, good-natured Helen and Richard have fallen for two such monster egotists as the widowed Mrs Wislack and the bankrupt Duke of Bristol?
Peter Hall's production offers half an answer in Martin Jarvis's performance of the Duke as a leathery playboy so enraptured with his own devastating charm that he really does become rather likeable, and only turns openly boorish when denied the key of the drinks cupboard. But maybe La Wislack is irreclaimable: Anna Carteret plays her in the standard judgemental manner, so that while she has comic value as an undeflatable punchbag, it is only when Richard (an unrecognisably bespectacled Simon Ward) starts thumping it that their relationship makes sense. Louise Lombard plays Helen with impenetrable sang- froid, handling her cigarette with an elaboration normally reserved for the Restoration fan. The comedy is foolproof, and some interesting thought has gone into this revival.
The all-conquering protagonist of Jules Romains's 1923 Doctor Knock takes over a sleepy village practice and turns it into a goldmine by convincing its heedlessly robust inhabitants that they are in urgent need of medical care. This is not another French satire on the medical profession. It is a fable on the mechanics of mass conversion. In Sam Walters's production, whipped along by the orchestral gallops of Milhaud and Ibert,
it develops a farcical pace that overcomes the repetitious plotting, and finally chills the blood when Geoffrey Beevers's Knock surveys his domain: a night sky illuminated not by stars but by the night-lights of his brain-washed patients, with '250 rectal thermometers lifted in unison'. A fine revival of a comic masterpiece.
Devised and performed by a company of five, Indhu Rubasingham's revue, D'Yer Eat with Your Fingers?], aims to give a voice to young British Asians. It clocks up some telling points in sketches about immigration controls, arranged marriages and parents who have never mentally quit the homeland. The writing is not wonderful. But the company is terrific, in personality and physical skills, including traditional Indian dance, Bhangra, tap, and French pantomime. Nina Wadia and Akbar Kurtha's cross-cultural pas de deux in ankle bells and tap shoes expresses racial harmony in a way that leaves language far behind.
The theatrical revelation of this year's Edinburgh Festival, Tom Courtenay's one-man Moscow Stations, has arrived at the Garrick. At once a personal confession and the cry of a suffering country, it demonstrates as piercingly as any work I have seen that all great comedy is rooted in pain. No one who cares for the future of Russia or the art of acting should miss it.
'What a Performance': Queen's, 071-494 5040. 'On Approval': Playhouse, 071-839 4401. 'Dr Knock': Orange Tree, 081-940 3633. 'D'Yer Eat with your Fingers?]': Royal, Stratford East, 081-534 0310. 'Moscow Stations': Garrick, 071-494 5085.