Bang On A Can, LSO St Luke's, London

Perhaps the Belgians are a more literal lot - though it's more likely to have been a terminal case of postmodern irony. Or maybe the cause of the polite rather than enthusiastic reception the group received from the much smaller crowd in London was the programme's different first half.

The London event opened with Tan Dun's Concerto for Six, a genuine synthesis of Tan's typical Chinese cries and whispers with jazz riffs and jazz-inspired improvisation for each of this crack group of performers in turn, though riskily static as a whole.

David Lang, one of BoaC's founding composers, is presently underrated in my view, but his two Songs for Lou Reed set classic Reed texts - "Sunday Morning" and "Heroin" - with a level of chromaticism that, combined with the expected restless, persistent angst, made very heavy weather of Reed's ruminations. They were sung, with a welcome lack of affectation, by Evan Ziporyn, the group's clarinettist; and his own Music from Shadowbang, concluding the first half, makes original and inventive play with its Balinese sources.

But the main focus of the evening was on Iva Bittova, for whom BoaC becomes a four-piece backing band for much of this second-half sequence of her own songs, plus some later instrumentals with the full sextet, entitled Elida after a poem by Vera Chase. Bittova's brand of singing - a kind of cross between cabaret diva, folk singer and avant-garde performance artist, who often plays the violin as she sings, is now fairly familiar here.

She's a capable performer, with an engagingly unusual persona, and with the conviction to get across most of her more theatrical antics - including arriving from the auditorium, and a variety of gestures (at one moment she appeared to be eating her violin) - without embarrassment.

I enjoyed her performance - and that of the BoaC musicians, who get their own moment of glory later on in this cleverly devised sequence - more in London than in Brussels. Yet even in the more intimate atmosphere of St Luke's, she didn't really grab me as the best cabaret singers do. But she roused this audience from what had earlier seemed near stupor.