The Slow Drag, Whitehall Theatre The Boys in the Band, Aldwych Theatre
"I was a self-made man: that's what this country's all about," announces Johnny Christmas. He ain't kidding. On his death, the coroner reveals to his children that their father was actually a woman. If you think that's far-fetched, bear in mind that Carson Kreitzer's The Slow Drag is based on the real-life story of jazz player Dorothy Lucille Tipton who passed as a man for nearly sixty years. This was back when swing was king and the only place for a woman was as a singer.

Theatreland is currently obsessed with necrophilia, disinterring the remains of the famous. Kreitzer, however, bucks the graverobbing trend by eschewing the dull chronological trawl and opting for fiction. Nor is she content merely to discover how such an explosive secret could be kept. Instead, she takes the conundrum and treats it like a diamond, constantly cutting it to show different facets of this fascinating tale. The structure of the characters meeting up after Johnny's death to retell their stories ought to be cheesy, but despite the odd longueur towards the end, the immediacy and the intimacy of Lisa Forrell's extremely well-cast production (with smart musical staging by Bill Dreamer) is extremely seductive.

The band is hot and the singing hotter. Kim Criswell, in addition to floating Oscar Levant's supremely wistful "Blame It On My Youth" and setting the place on fire with Harold Arlen's great "Blues in the Night", is surprisingly touching as the love of Johnny's life, while lithe Christopher Colquohoun is marvellously relaxed as Chester, the pale-skinned black musician who joins Billy's all-white band. As Johnny, the excellent Liza Sadovy plays the sax, sings like a male crooner and adopts a gruff, tough Jimmy Cagney manner which cunningly underlines the bizarrely traditional demands Johnny makes of his wife. First seen at the tiny Freedom Cafe, this West End transfer deserves to be a great success.

The Boys in the Band is also a fringe transfer, now playing the 1200- seat Aldwych Theatre. The 1968 play originally seemed like a wildlife documentary, as if playwright Matt Crowley were revealing the secret life of a peculiarly elusive species: the homosexual. Now its principal interest is as a period piece. Gay men these days have better things to do on a couch than be straightened out. But it's not only the politics that have dated. When did you last see a play where the second half begins with the cast in exactly the same poses as at the curtain line of Act One? When did you last see a drinks trolley? Speaking of which, when did the cast last have a drink? Judging by some of the "drunk acting", 1968.

Not all the sober acting is that great either, though most of the cast can play the comedy in Crowley's often sharply funny lines, but the texture- free direction is way too slack to cope with the excesses of Act Two with its nightmare truth game which might as well be called "Dial H for Humiliation".