Lady Day, New End Theatre, London

Hair pulled back tight into a snood, clinging white-satin gown, white platform shoes – Dawn Hope is kitted out just like Billie Holiday in the Forties. But it's 1959, and she's rather overdressed for the venue – the full title of Lanie Robertson's play is Lady Day at Emerson's Bar & Grill. The nightspot is in Philadelphia, a place about which Holiday shares the opinion of WC Fields, but at this point, just a few months from her death at 44, she doesn't have much choice. The DJs, she tells us, are calling her "Lady Yesterday'', the parole officers are waiting for her to make a false step, and though no longer fixated on white gardenias (she used to be unable to perform without them in her hair; now they're on her wrist), we can only think of their symbolic value and have our doubts.

I can't say I was thrilled at the prospect of yet another show with a cast of one, especially an impersonation of such a distinctive singer. But Lady Day, if predictable in its portrayal of Holiday's grim past and present, is a convincing and well- structured piece of work. Hope's pleasant contralto lacks theeerie, bewitching quality that made Holiday unique, but too close a resemblance might have made us concentrate on her ability to imitate a voice rather than summon up a spirit. Her renditions of Holiday's repertoire are good enough not to outrage any fan. Her defiant, even vehement, version of "God Bless the Child'', quite unlike Holiday's rueful style, was quite impressive in its own right.

Holiday's life certainly provided ample material for a blues singer -- or, in her case, a jazz singer with a blues feeling. She graduated from scrubbing the steps of a whorehouse as a child to working in one a few years later. Her mother thought she was going there to be a maid. "She wasn't too much older than me, and she wasn't a hell of a lot smarter either.'' Her first husband, Sonny, who her mother said was "the only coloured man she'd ever seen who was blacker on the inside'', got her to take drugs, saying it would make him feel she really loved him. This speech, in which we see the neglected, love-starved child desperate to prove herself worthy of love, is painfully moving and realistic – Hope conveys Holiday's fragility by contrasting her bright – sometimes too-bright – speech and gestures with her posture and gait. When she turns and walks to the pianist (Warren Wills, who provides splendid musical and emotional support), she is shockingly bent and halting.

Lady Day could do with more light in the gloom – the story of how she and Artie Shaw's band put a Southern racist's nose out of joint is delightful for the chance it gives Hope to be vivacious and gleeful. But these dark reminiscences pungently evoke the story of a woman who said: "Singin's always been the best part o' livin' to me.''

To 8 September (020-7794 0022)