Things can only get blacker

The voice is extreme, but no less than her performances. In her latest work, Defixiones , Diamanda Galás takes on genocide

The Greek-American singer-songwriter Diamanda Galás - whose latest show, Defixiones, Will and Testament, comes to the Barbican on Thursday as part of the Centre's "Only Connect" festival - has long had a reputation as the Scream Queen. Her four- (or is it a mere three-and-a-half-?) octave voice was classically, even operatically trained; Frank Kelly, a bel canto specialist, was her teacher for 10 years. But, even as a student in San Diego in the mid-Seventies, she was extending her vocal equipment to territory Western classical music doesn't ever reach; one of her earliest inspirations was the British soprano saxophonist Evan Parker.

The Greek-American singer-songwriter Diamanda Galás - whose latest show, Defixiones, Will and Testament, comes to the Barbican on Thursday as part of the Centre's "Only Connect" festival - has long had a reputation as the Scream Queen. Her four- (or is it a mere three-and-a-half-?) octave voice was classically, even operatically trained; Frank Kelly, a bel canto specialist, was her teacher for 10 years. But, even as a student in San Diego in the mid-Seventies, she was extending her vocal equipment to territory Western classical music doesn't ever reach; one of her earliest inspirations was the British soprano saxophonist Evan Parker.

Since the early Eighties, this now 44-year-old purveyor of satanic verses has been regaling us with concerts and albums castigating hypocrisy in Church and state, and focusing in particular upon reactions to the Aids crisis. Galás's manner of presentation has usually, like her vocal declamation, been extreme; her 1991 live album, Plague Mass, was recorded in New York's Cathedral of St John the Divine with its protagonist stripped to the waist and covered in blood.

Among my preparatory homework, gleaned from her several websites, was an interview in Terrorizer magazine: not the sort of regular reading favoured by those of us leading more sheltered lives. Fellow journalists, too, had warned me that this angry lady eats journalists for breakfast - though one of them did try to reassure me by suggesting that she probably never eats breakfast anyway. Our 11am appointment, on the day following the first New York performance of Defixiones last week, did not inspire confidence. But at least we were meeting in a Manhattan corner café with a good escape route...

As it turned out, I needn't have worried. Offstage, the all-black attire and long, flowing black hair may help to turn heads in the street. Close up, you can read the words "We are all HIV+" tattooed on the knuckles of her left hand; Galás, in fact, openly confesses to having had hepatitis C, which I gather carries a similar threat. But, behind the dark glasses, I thought I caught more looks of concern for her interviewer's health and well-being, on his 48-hour excursion to a more than usually chilly New York City, than flashes of devilish venom.

Premiÿred in the appropriately lugubrious setting of Ghent's Castle, Gravensteen in September, Defixiones (the word refers to the warnings engraved in lead that were placed on the graves of the dead in Greece and Asia Minor) is a "song cycle for voice and piano" in several languages. It is performed by Galás alone, moving back and forth from a single spot for unaccompanied items to the piano, which she attacks with vigour in occasional solos as well as accompaniments rich in allusions to a range of styles - from blues and jazz to Western classical to the Armenian, Anatolian Greek and Syrian cultures providing the source for several of the work's texts, which also draw tellingly on the Belgian poet Henri Michaux.

Though often describing herself as Greek, Galás herself has Armenian, Turkish and Syrian ancestry. Extrapolating its theme from Turkish culture past and present, the cycle is dedicated to the forgotten victims of the Armenian and Anatolian Greek genocides of 1915 and 1922. In performance, Rudi Pribitzer's lighting reinforces the gloom of her subject matter; in New York's The Kitchen (a much smaller venue than the Barbican, which serves to stress the intimacy of the whole experience), Galás could seem both frail as well as feisty.

The hour-and-a-quarter show proves to be Galás's more recently familiar mixture of her own material and music by others, which more directly reflects the popular traditions that help determine her approach. To say that she has calmed down now would be somewhat wide of the mark; for one thing, she says that she has always sung familiar popular repertoires - standards and earlier jazz styles, for instance - but not, until now, on recordings, which have been chiefly of her own material.

Galás's 1993 album Vena Cava, and the 1994 Sporting Life, her more overtly rock collaboration with John Paul Jones, do suggest a more popular approach. Yet only a couple of years later Schrei X was, as she puts it, "a pretty extreme record". And any suggestion that she is narrowing her options, or even content just with the "extended vocal techniques", is forcefully opposed. "I work in parallel ways. If you sing a blues by John Lee Hooker, and suddenly you're just imposing a set of 'vocal techniques' in the middle of the piece that has nothing to do with it, that's absurd musically." She is also scarcely suited temperamentally to staying in the sound laboratory where she first - very secretively, which is surprising - experimented with her voice. "My raison d'être is singing, is music," she insists. Some of the songs in Defixiones she describes as "cabaristic, in that Brechtian-Weill sense".

The prevailing theme of exile is reflected in Defixiones in a wide variety of poetic sources and styles. The interleaving of texts by the Armenian poet Siamento and the Syrian poet Adonis, which opens the work, powerfully integrates solo and accompanied vocal lines, including a liturgical melody ("Ter Voghormia" by Marar Yekmalian), with recitation and some highly unsettling drones on tape. The affectingly simple repetitions and ululations of her arrangement of Ornette Coleman's "Lonely Woman" offer some respite between the obsessive low monotone of Galás's own "Birds of Death" and Hooker's "Burning Hell"; the latter is faster, jazzier and infiltrated by tape delays applied both to vocals and to piano (courtesy of Blaise Dupuy's "sound design").

The two Greek Rembetika songs included were made famous earlier in the century by Sotiria Bellou, a lesbian who added a new dimension to the defiant but misogynistic Rembetika tradition of her time. This was, Galás says, "ethnically cleansed" during the Papadopoulos regime, but has just recently been revived - by Bellou's powerful, low voice and confrontational manner. (Galás describes her as "real scary-looking", so you can bet that Bellou would have most of us running.)

The exiled visionary Peruvian poet César Vallejo inspires some wild keyboard outbursts, including pitch-bending and overlays, as well as a vocal line of chilling lyric impact. The screaming and the multiphonics emerge only occasionally, made all the more powerful by their contrast to the unhinged mayhem that has preceded them. Galás's version of the well-known negro spiritual "Let My People Go" - familiar, like her own "Birds of Death", from her 1988 album You Must Be Certain of the Devil - concludes Defixiones with a kind of built-in encore. "It's just," she says disarmingly, "an old song that everyone knows";and it fits the exile theme perfectly.

Galás currently seems to be further expanding her range in Nekropolis, an opera on which she is currently working. A development out of both the Plague Mass and Insekta projects, this may be premiÿred in 2001. Though unwilling to divulge much information about it, she says that this work - which she hopes will include a larger ensemble than she's ever used before - extends the idea of the City of the Dead to deal "with populations that have been hidden from main society, like severely retarded individuals, forsaken by their families, who have been made available for research".

'Defixiones', 9 Dec, Barbican, 0171-638 8891