Blonde Bombshells Of 1943, Hampstead Theatre, London <!-- none onestar twostar fourstar fivestar -->

As they sing in one of the songs here: "It ain't what ya do, it's the way that ya do it''. Style certainly predominates over substance in Blonde Bombshells of 1943, a slight but delightful musical play by Alan Plater now receiving its London premiere at Hampstead Theatre in Mark Babych's engaging co-production with the Octagon, Bolton.

This stage-piece is a kind of prequel to Plater's 2001 television drama, The Last of the Blonde Bombshells, which starred Judi Dench and told the story of an all-woman band that reformed after 50-odd years apart. As the title indicates, Blonde Bombshells of 1943 imagines such an outfit - inspired by the redoubtable real-life Ivy Benson's band - in the thick of it.

There's a simple but effective framing-device that intensifies the throb of nostalgia. At the start, a young modern-day narrator, Liz (Karen Paullada), begins to tell us of the "hell of a day'' when her then-schoolgirl grandmother (played by the same actress) learned about "love, sex, betrayal and death'' in a heady crash course on life. The show goes into lengthy flashback.

The Blonde Bombshells are up against it. On a recent tour of American bases, they've lost four of their members, who succumbed in unsisterly fashion to the charms of the GIs. As they are due to headline a concert for a morale-boosting BBC broadcast that night, they need to find replacements double-quick. There's a motley crew of contenders: a naive schoolgirl clarinettist; a singing nun (Claire Storey) who performs George Formby numbers in blissful ignorance of innuendo; an impossibly posh saxophonist (Rosie Jenkins); and a male drummer (Chris Grahamson) who's willing to don a frock in order to dodge his calling-up papers. The formulaic quality of all this is redeemed by the comic Northern charm of the writing and of the admirably versatile actor-musicians. Disappointingly little, though, is done with the theme of wartime female empowerment and nothing is tackled in any depth.

I saw the show on the second night and a youthful audience went wild for the feast of live swing - Andrews Sisters numbers, tributes to Flanagan and Allen and Gracie Fields et al - in the knock-out concert in the second half.

To 12 August (020-7722 9301)