George Gershwin Alone, Duchess Theatre, London

The title of this show sounds like an oxymoron. When was George Gershwin ever alone? The most sociable of composers, he even wrote music in company, creating his biggest hit, "Swanee," with lyricist Irving Caesar alongside a lively poker game at his family home. When it was finished, they pounded out chorus after chorus for the enthusiastic players, while Gershwin père made a trio, with tissue paper and a comb. Popular with the ladies, Gershwin was seldom alone at night, and his routine domination of innumerable parties led one of his friends to say, "An evening with George Gershwin is a George Gershwin evening".

Impersonating George, Hershey Felder doesn't describe the joyful genesis of "Swanee" but a misleading version of its discovery by the star who made it a hit. As Felder tells it, the unknown 20-year-old Gershwin, was playing piano at a party and decided to let loose with his new composition. When a man shouted at him, Felder has Gershwin saying, he feared he would be thrown out, but it was Al Jolson, saying, "I must have that song". While the incident itself is true, its portrayal of Gershwin's circumstances is a lie: Far from being obscure, Gershwin had already written the score for a Broadway show. "Swanee" was already part of a Broadway production - ironically, one playing across the road from a revue starring Jolson, who, had never heard it.

Felder accentuates the negative to highlight his unique slant on the Gershwin legend. In this show, the attractive, vital, enormously successful musician becomes the star of a hard-luck story. There's a brief acknowledgment of his wealth - when he asks Ravel ("the French composer," Felder adds helpfully) for lessons, Ravel asks what he's making and, when told, says, "I should take lessons from you". But Felder's Gershwin constantly pleads for our sympathy. He recites, with a hangdog look, the pains of his serious compositions, implying that the reviewers were united. (They weren't; many raved.)

You can't feel too sorry for someone surrounded, as Gershwin was all his adult life, by the rich and glamorous, so Felder doesn't mention them. Instead, he tells anecdotes of Gershwin's yiddish mama and papa, portraying the former as a termagant and quoting the latter's unenthusiastic reception of the satirical show Strike Up the Band as if it referred to his son's entire output.

The Jewish note is stressed as much, and as falsely, as the pathetic. After discussing the 1935 production of Porgy and Bess, Felder/Gershwin repeats a scabrous attack on Jewish music, which mentionsRhapsody in Blue in the anti-Semitic Dearborn Independent. Odd, you might think, that the paper should single out a piece of 11 years earlier, and you'd be right: it closed down in 1927. Felder's time-link to the fate of European Jewry is as spurious as his implication that Gershwin was harmed by the racist rag.

After he stops being Gershwin, Felder is himself again and leads the audience in a sing-song, pausing at the end of each line of "S'wonderful" or "Love Is Here to Stay" to give the lyrics for the next. The proper purpose of this show is then clear: an entertainment, full of resentment and sentiment, in a Jewish old-age home - which has for some time been a definition of Gershwin Alone's original venue, Broadway.

To 17 April (020-7494 5075)