Fanciful tale of a captured diva springs a surprise at Orange fiction awards

The Orange prize for fiction by women sprang another of its regular surprises yesterday when the £30,000 award went to the least-liked novel among visitors to the sponsor's website.

The judges' winner, Bel Canto, by the American writer Ann Patchett, picked up only 10 per cent of votes on the official site. Its low popular appeal contrasts with the 35 per cent scored by the readers' and bookies' favourite, the highly praised Victorian mystery Fingersmith, by Sarah Waters. It also defeated Helen Dunmore's acclaimed novel of wartime Leningrad, The Siege, and Maggie Gee's challenging drama of racism and reconciliation in London today, The White Family.

Suitably enough, Bel Canto, which has an opera singer for its heroine, sailed off with the prize at a ceremony in the Floral Hall of the Royal Opera House, Covent Garden. Patchett's book, published in the UK by Rupert Murdoch's imprint Fourth Estate, had been the 6–1 outsider on a shortlist of six.

The judging panel was headed by the retired radio presenter Sue MacGregor. It included the Cambridge professor of English, Gillian Beer, the actress Fiona Shaw, and A L Kennedy, a Scottish novelist who recently claimed that drug-taking and sexual favours influenced the outcome of the Booker prize.

Patchett was born in Los Angeles in 1963 and now lives in Nashville. Bel Canto was her fourth novel.

Her victory follows other unexpected choices by Orange juries, such as last year's preference for the little-known Australian novelist Kate Grenville over Margaret Atwood, and Suzanne Berne's triumph over Toni Morrison in 1999. The reputations of Morrison and Atwood do not seem to have suffered as a result.

Patchett's book, set in an unnamed Latin American state, deals in a fanciful and artificial style with the capture of an American opera diva and her audience by terrorists during a private recital.

The leading American soprano Renée Fleming has recently said that Bel Canto is "about me", and is attempting to have the book made into a film. Fleming noted that two favourite parts of the fictional singer, Roxane Coss, correspond to her own signature roles: Handel's Alcina and Dvorak's Rusalka. Fleming and Patchett recently appeared together at the Lincoln Centre in New York to discuss the novel's premise that the power of music can bring political adversaries together.

Taking its manner and structure from musical models, Bel Canto presents the incursion of comic-opera bandits into a soirée attended by a variety of national stereotypes: French, Russians, Germans, Italians. The concert has been arranged to flatter a visiting Japanese electronics mogul, but the country's president decides instead to stay at home and watch a much-loved soap. During the ensuing months of siege at the vice-president's mansion, two imprisoned couples fall in love. Meanwhile, the presence of a translator – Gen – signals the underlying theme of cross-cultural communications and confusions.

The stiffness of the characters, the melodrama of the plot and the absence of reality in the South American context mean that Bel Canto sticks, more closely than Patchett might have wished, to its stagebound conventions. The book, like the romantic opera repertoire it mimics, is an entertaining contrivance that sacrifices plausibility to bravura arias or set-piece dialogues. At one point, the young lovestruck terrorist Carmen asks: "How much luck is one person entitled to in a night?" After her sweet confection swamped the stronger flavours also on the menu of the Orange shortlist, Ann Patchett would be entitled to reply: an awful lot.

'Bel Canto': An extract

There were those who believed they would be killed, who over and over again saw the movie of themselves being led out the door at night and shot in the back of the head, but Roxane Coss thought no such thing. Maybe there would be a bad outcome for some of the others, but no one was going to shoot a soprano. She was prepared to be nice, to let her hand be held, but when the time was right she would be the one to get away. She was sure of it. She smiled at the boy when he opened the door to the bathroom for her. She half expected he would follow her inside. When he didn't she locked the door, sat down on the toilet, and cried, great gulping sobs. She wrapped her hair around her hands and covered her eyes. Goddamn her agent who said this was worth all the money! Her neck was stiff and she felt like she might be getting a cold, but who wouldn't catch a cold sleeping on a floor. Wasn't she Tosca? Hadn't she jumped off the back of the Castle Sant' Angelo night after night? Tosca was harder than this. After this she would only play in Italy, England and America. Italy, England and America. She said the three words over and over again until she could regulate her breathing and was able to stop the crying.