Oh, What a Lovely War!, Open Air, Regent's Park, London<br></br>The Resistible Rise of Arturo Ui, Bridewell, London<br></br>The Birds, NT Lyttelton, London<br></br>Cabaret, Festival Theatre, Chichester

Innocence all blown to hell

You don't expect to be shell-shocked by an al fresco musical in Regent's Park. Ordinarily here, life and art are a picnic, more or less literally. But Oh, What a Lovely War! – while being tuneful and entertaining – is a barbed, heart-rending history lesson. We should give artistic director Ian Talbot a medal for such comparatively bold programming and a fine production.

This persuasively pacifist, tragi-satirical chronicle of the First World War – devised in 1963 by Joan Littlewood's left-wing troupe, Theatre Workshop – may sound badly dated on paper. The cast are costumed as pierrots and ape bygone end-of-the-pier shows, launching into comic sketches and vintage songs ("Belgium Put the Kibosh on the Kaiser" et al). Yet Talbot's ensemble make this seem, on the whole, fresh and vital.

Firstly, the Open Air crowd is easily transported to the seaside setting: a wooden prom with a live band in a stand. And everybody is happy to be jollied along by the gag-mongering Master of Ceremonies and his chorus line. Then we start to play the ironically named "War Game", moving towards blacker humour and some poignant glimpses of long-suffering lads on the front. The trenches are created with a heap of Edwardian garden chairs – suggesting an age of innocence being blown to hell. Plummy commanding officers, with their silk pantaloons tucked into long boots, make risibly foolish battle plans in Franglais with sniffy Gallic counterparts. Keen Irish fusiliers rush in, dancing a reel, and are gunned down.

Some of the sketches certainly drag, with the lampooning of high society profiteers being notably prolix. But John Hodgkinson is a hugely funny sergeant, yelling gobbledegook like a retching turkey. And crucially, the tension mounts between the tomfoolery on stage and the devastating, Brechtian news headlines and statistics projected above ("February, Verdun: One And A Half Million Lost"; "Somme: 60,000, First Day").

The use of period songs is also potent and complex, understanding as well as damning the "join-up and chin-up" spirit of 1914 before pushing on to the acute bitter-sweetness of "When This Lousy War Is Over" (choired to the tune of "What a Friend I Have in Jesus"). The man across the aisle from me couldn't fight back the tears.

The Resistible Rise of Arturo Ui is a disappointing new adaptation by Andy de la Tour of the mafia saga-cum-Third Reich allegory which Brecht (part-inspired by US gangster movies and Chaplin's The Great Dictator) penned in exile in 1941. Phil Willmott's production looks good with slanting lamplight and shady figures in trilbies. As the hoodlum who muscles his way to the top of the heap in depression-stricken Chicago (acquiring Hitleresque lip hair en route), Peter Polycarpou's Ui is a ball of malign energy – like a remorseless pit bull.

Overall though, this show hardly gets old Bertolt's agitprop theories working. Most of the acting is superficially urgent. Ui's oratorical rants are numbing and in-your-face in the tiny Bridewell. Others didactic choric asides are hardly an antidote. Moreover, though fascists and dubious links between politicians and the business world are surely topical today, de la Tour's excision of Brecht's original captions (which referred to real events in Nazi Germany) leave Ui's episodic rise looking peculiarly scrappy and insignificant. Instead of stimulating you to fight against corruption, you end up as glazed as the lamentably passive citizens on stage.

As if one wasn't enough, we have to endure another moustachioed dictator in The Birds, Aristophanes' mocking fantasy wherein a lowly Athenian opportunist called Pez (Marcello Magni) gets to rule the roost and spoils the utopian realm of our feathered friends. In the Lyttelton's far-from-wonderful Transformation season, Kathryn Hunter's production with acrobats gets physically, but never metaphorically, off the ground. Wearing beaky masks, her corps of trampoline and trapeze artists (from Mamaloucos Circus) display fab gymnastic skills. Spinning through the void like propellers, they land, with complete cool, on hair-raising perches, while some whizz out teasingly over the audience.

But this is a flop as drama. All the spectacular fluttering distracts from the resistible rise of Pez without managing to conceal that his storyline is sketchy. Magni keeps fluffing his lines while his sidekicks, the normally scintillating Josette Bushell-Mingo and Hayley Carmichael, hardly get to unfurl their wings. Hunter and Sean O'Brien's adaptation has linguistic bounce, yet it is bird-brained as an updated satire, taking scatty pot-shots at anything from the Führer to the Statue of Liberty and missing every mark.

Far better is Chichester Festival's revival of Cabaret, Kander and Ebb's 1966 hit which centres around Berlin's decadent, sexually liberal Kit Kat Klub in 1929 as the threatening storm clouds of Nazism gather overhead. At its best this is a outstandingly edgy musical that worries about when exactly boho laissez-faire attitudes become fatal carelessness that lets would-be repressors get control.

Julian Bleach (ofShockheaded Peter fame) is frighteningly ghoulish and noncommittal as the KKK's white-faced, black-lipped, kinky Emcee. His deadpan love song to a Gorilla suit/supposed Jewess, entitled "If only you could see her through my eyes", is alarmingly double-edged. Roger Redfarn has done an admirable job as replacement director after Lucy Bailey departed over "artistic differences" with the Festival Theatre. The real snag is Alexandra Jay (the acclaimed understudy from the National's My Fair Lady) starring as the roving chanteuse Sally Bowles without any messed-up vulnerability under her brassiness. So you wonder why William Rycroft's gentle, novel-writing Cliff embraces her at all. A problematically shallow central performance.

k.bassett@independent.co.uk

'Oh, What A Lovely War!': Open Air, London NW1 (020 7486 2431), to 3 Sept; 'The Resistible Rise of Arturo Ui': Bridewell, London EC4 (020 7936 3456), to 24 Aug; 'The Birds': NT Lyttelton, London SE1 (020 742 3000), to 14 Aug, then touring; 'Cabaret': Festival Theatre, Chichester (01243 781 312), to 5 Oct