Women Across The World, Floral Hall, Royal Opera House, London <!-- none onestar twostar threestar fivestar -->

While English National Opera prepares its Asian dub collaboration, the Royal Opera House pursues parallel experiments: first with its Nitro series of mini-operas by black composers, and now OperaWorld/ WorldMusic, which asks how mainstream European opera might be influenced by other cultures.

John Lloyd Davies, director of this new strand, adduces Debussy and Britten as composers whose dunking in the music of Indonesia had fruitful symphonic results: over the past week, he has programmed the Irish folk musician Iarla O'Lionaird, the Mauretanian singer Daby Toure, and the eclectic Baghdaddies.

And if the finale had only the slenderest connection with opera, those who gathered on Sunday afternoon in the Floral Hall got a rare and stimulating treat.

Mostly used as a café, this airy space makes a wonderful concert venue, and when Helen Chadwick and her singers appeared on a balcony, the effect was pure theatre. Their first song was inspired by her researches into Bulgarian singing, and its hard-toned polyphony, with its Georgian harmonic tinge, was thrilling.

Next came Tiger Dream in Forest Green, by Eleanor Alberga, brilliantly performed by instrumentalists from the Covent Garden orchestra. The programme noted that this work "germinated from an environmental concept, but quickly became more". It was certainly a sparky chamber piece, but it wasn't helped by the gloss put on it.

But the hall was galvanised when Chadwick and co delivered a series of short songs. The first relied on gentle hocketing, but made much out of little; the second played games with an asymmetric dance rhythm she'd found in Bolivia; the third married the bagualas rhythm from Argentina with a ground bass from Rwanda.

The final work was Dominique Le Gendre's Tales of the Islands, consisting of poems by fellow-Trinidadian Derek Walcott with her musical responses. Read by Sir Willard White, whose voice perfectly suited their marmoreal strength, these verses gave rise to some gorgeously variegated short pieces: Le Gendre is a composer to watch.