The Slow Drag, Whitehall Theatre, London SW1 (0171-369 1735)

Liza Sadovy, a peerless Susanna in The Marriage of Figaro and notably good in the recent revival of Sondheim's Company, has been to the hairdresser. Not normally "hold the front page" stuff, but she's said goodbye to locks in order to play a jazz musician who was a man... only he wasn't. (We're in As you Like It territory, I think.) The character of Johnnie Christmas is based on the real-life figure of Dorothy Lucille Tipton, who spent 50 years successfully masquerading as male sax-player and jazz pianist Billy Tipton. Since its first outing earlier this year, the show has been considerably revamped, but playwright Carson Kreitzer's smartest move has been to take the idea and go fictional on it. Freed from the shackles of fact, his characters can pursue more dramatic trajectories than the truth mapped out for the originals. It's an all too rare decision.