Goran Bregović, Barbican, London

Goran Bregović has devised the sort of folly that only an internationally acclaimed composer who divides his time between Belgrade and Paris could come up with. Margot: Diary of an Unhappy Queen is a theatre-concert hybrid linking the lives of a woman in Sarajevo during the Bosnian war and a 16th-century French queen. The concert part, involving Bregović and 18 other musicians and singers, was excellent. The theatrical element, floridly overacted by Irish actress Lisa Dwan, was risible.

It opened with Bregović on stage alone in a brilliant white suit playing the electric guitar. Originally from Sarajevo, he was the leader of Bijelo Dugme, one of Yugoslavia’s most popular rock bands. Going solo, he became an inspired pop-rock interpreter of the region’s gypsy music, forging a fruitful partnership with the film-maker Emir Kusturica. Having fled to Paris during the Yugoslav wars, he widened his film soundtrack work to French cinema, including the 1994 costume drama La Reine Margot. That, unhappily, was the seed that spawned the misshapen creation of Margot: Diary of an Unhappy Queen.

The first 30 minutes were misleadingly impressive. Blasts of brass and clarinet and a thumping turbo-folk beat filled the auditorium as musicians joined Bregović; the song was “Kalasnjikov”, the soundtrack to a wild party, all gleaming gold teeth and celebratory gun-play. Then the mood switched as a string section led the music in a slower, darker direction. Two women singers in traditional Balkan outfits were accompanied by a choir of operatic male singers in black tie. The style flickered back and forth suggestively between modern classical and Balkan folk-rock.

Then Dwan came on stage, and the show careened off course. She played the part of a general’s daughter in Sarajevo whose husband has been sent to the front line and whose mother has gone insane. She finds a diary supposedly written by the 16th-century French queen Margot, about the civil war between Catholics and Protestants. Actually – spoiler alert – the “diary” was written by her mad mum.

The historical parallel was vapid, designed for consumption on the international festival circuit; meanwhile words I never thought I’d hear uttered on a stage – “Men are sweating, mad with the smell of mating”, “Bosoms were everywhere!” – resounded around the auditorium. The audience grew restive. Poor Dwan headed gamely over the top, but her part was unsalvageable. Bregović tried to rescue proceedings with an extended encore of drinking songs; they merely underlined the extent of the project’s folly.

www.barbican.org.uk