The Barbican Centre, London
There was a time, not so long ago, when all Bulgaria meant to me was red wine and wombles. Then I discovered - officially, The Bulgarian State Television Female Vocal Choir. Established in 1952, their function was to perform concerts for state broadcasts, and thus they might have remained a national secret. But tours to other Eastern-bloc countries led to larger acclaim when, in 1987, America and the UK (two albums were released that year on 4AD) became aware of their sound, an eerie, elemental ululation. Bulgaria has a colourful history - including five centuries of bloodshed and occupation under the Ottomans - and the women, combed from towns and rural villages, are recruited as apprentices of the folk songs and stylings of their homes: from Western Shope and Pirin, sparse melodies over a low, sustained tone; from the Thracian plain, a terrifying vibrato; from the north, ornamentation as delicate as the embroidery on a wedding dress.
Tonight, they troop on stage in national costume, exotic and identical to the last flower on a headdress. Each holds out an arm for her neighbour to clasp. Twenty-three faces, some barely out of their teens, some in their late fifties, some homely, some startlingly lovely, a catwalk's worth of Slavic cheekbones. They smile benignly and you imagine our equivalent, a group of students and grandmothers from, say, Thornton Heath to Thurso. Then they open their mouths and casually unleash a sound like sabres clashing, softening to something like the lonesome cry of birds. These unaccompanied voices aren't soft, rarely sweet, though there's an eroticism Kate Bush exploited (you can hear them on The Sensual World). It's a hard, organic noise, bounced against the thorax and forced up from chests like shields. The secret's in the genes, a configuration of inordinately strong muscles - as an expatriate Bulgar ensemble in the US discovered, when they experimented and damaged their vocal cords. Now, as the voices rise, the shock hits you like an icy waterfall, its chilly rivulets running down your back. You know these are stories of love, death, birth or seasons changing because a sheet of notes tells you; but you can get the sense from a heartbroken drone, or fluting, flirtatious yelps of joy. Soloists and quartets occasionally take front stage, and the feeling changes again; the women become houris, lush, threatening and unknowable, or seem to wink at us, with gossipy, girlish laughter; even when a soloist gets a standing ovation, there's no jealous narrowing of eyes. Siren songs from thousands of miles away - and they're dragged back for encores until they start to cough.