MUSIC / Singcircle - St Giles Cripplegate, EC2

Having opened their autumn season with a diversity of solo performance-styles, the New Macnaghten 'Vocal Projections' series continued on Thursday with Gregory Rose's Singcircle, offering a manifesto of works for unaccompanied voices. Live electronics were directed by composer Stephen Montague, whose Tigida Pipa of 1983 used invented words as the basis for a bracing exercise in rhythm. Other pieces preferred poetry-derived phonemes for their substance: verses by the Irish writer John Montague in Michael Alcorn's A Slow Dance, for vocal quartet and computer sounds; fragments from Jacques Roubaud and Balzac in Kaija Saariaho's Nuits, adieux. For all their literary origins, what mattered here (and in Wayne Siegel's atmospheric Eclipse) was the fascination of structures derived from phonetic building blocks.

The polemic of Steve Martland's Terra Firma required different techniques. Polyrhythm and hocket in the faster movements kept the ear engaged with unremitting urgency. The poignant section called 'Skywalk' extended the challenge from the aural to the visual and symbolic senses for the only time that evening. It sounded like a 20th-century litany. The response lay in the audience's imagination.