THEATRE / Generating power in a black-out: Paul Taylor on a shattering version of Hecuba and the breezy June Moon

THE NIGHT I saw Hecuba at the Gate, there was a brief power-failure which plunged Laurence Boswell's fine production into pitch darkness. It came at a particularly nerve-racking moment, just as Hecuba, with the false bait of treasure, is busy luring her son's murderer, Thracian Polymestor, to her tent and to his doom. Sitting there tensely in the unscheduled Stygian blackness, you half expect the lights to jerk back on and disclose a scene of emetic butchery - bodies daubed over the wall, at the very least.

In the art of conveying moral horror, though, Greek tragedy needs no adventitious assistance from the Electricity Board. What Euripides and Boswell do consent to show is much worse than any video-nasty imaginings. In one chilling touch, the director has Polymestor's little boys - who have been kissed and conspiratorially clucked over by Hecuba as though invited to play some naughty, secret game with her against the Greeks - run down and pull their tarrying father off to the tent with an innocent, childish impatience. And when he emerges - blinded, blood-splattered, childless, bellowing - Ann Mitchell's impressive Hecuba watches his ravings with an intent but disturbingly detached curiosity, head to one side and a little appraising smile on her lips. You would think from her expression that he was merely acting out a role she had created for him - which, in one grisly sense, is correct.

The tiny Gate Theatre deviates from its normal practice by using a central stage on to which swarm the 12-strong female chorus, dressed in mourning, Greek Orthodox black, and giving vent to deafening harmonies which stray at moments a little too close to pop banality for comfort (or rather, discomfort). The moral deterioration in Hecuba - King Priam's widow, now a slave to the Greeks and condemned to live through the murder of her children - is compellingly charted by Mitchell. When Agamemnon (Sylvester Morand) asks her how she can bear all her suffering, Mitchell lolls back with a wheezy, half-crazed laugh against the mangled corpse of her son and says 'I'm dead, lord, I feel nothing.' It's but a short psychological step from this tragic, emotionally depleted state to the unblinking ruthlessness that enables this heroine to murder blameless children.

If 'pain leapfrogs pain' in Hecuba, wisecrack leapfrogs wisecrack in Alan Strachan's delightful production at Hampstead of June Moon, the snappy but soft-centred satire on Tin Pan Alley songsmiths written in 1929 by Ring Lardner and George S Kaufman. The best of these - like the observation that, if composers only write songs about their hometowns, then there must be an awfully big Jewish population in Tennessee - are provided by Frank Lazarus's Maxie, the benignly jaded, Jewish pianist at Goebel and Hart's. 'It's about a couple who have a baby without benefit of clergy - and you can dance to it,' explains one of the firm's employees as he sits down to play a new ditty - which gives you some measure of the size of the talents in this outfit.

Played with a gangling gaucheness that would make the young Jimmy Stewart look almost sedatedly relaxed, Adam Godley's marvellous Fred is a small-town boy from Schenectady who comes to New York to write lyrics and has a surprise hit, which causes him to forget the small-town girl he travelled up with (Maria Gough) and to waste his money instead on the gold-digging sister-in-law of his partner (Susannah Fellows), whose affection is almost as genuine and non-toxic as her hair-colouring. It all comes right in the end, though, which is odd because the love of the small-town couple comes straight out of the cliched songs the show is supposed to be satirising.

Strachan should cut the unnecessary musical finale, which has an embarrassing end-of-the-pier feel to it. Nearly everything else is a treat, though, and some of the performances, like Julia Blalock's acidulously disillusioned wife of a composer, have real bite. When you think of what has been transferred to the West End in the name of entertainment . . .

'Hecuba' is at the Gate, London W11 (071-229 0706); 'June Moon' is at the Hampstead Theatre, London NW3 (071-722 9301).