Here’s some compositional reverse engineering. Christopher Fox describes his Catalogue irraisoné (1999-2001) as a “parallel version of the same ideas in a different form” of his evening–long Everything You Need To Know . Defining Everything itself isn’t easy. Commissioned by the Ives Ensemble with a stipulation that they didn’t want conventionally formatted concert music, Fox devised a living and breathing sound installation using live instrumentalists and singers. Catalogue irraisoné distils that material for vocal ensemble Exaudi as “a guide . . . like a catalogue for an exhibition of visual art” to his large work. Everything you need to know about Everything You Need To Know .

Fox’s choice of text ranges from Dante and Virgil to an essay about artist Rachel Whiteread and an address by the president of Romania to the 1999 World Music Days; a puzzling compendium and, on a point of order, Metiér could have helped our comprehension by reproducing the texts. But were they omitted by design? Fox is experimenting, he says, with the distinction between song, speech and declamation, deliberately querying boundaries of comprehensibility, and Exaudi serve these technique-stretching demands keenly. Group director James Weeks snarls, shouts, and whispers text as he stamps on the floor in rhythm, bass voice Jimmy Holliday is locked into an obsessive-compulsive melodic loop that collects new modules additively, soprano Juliet Frasier duets with “natural” singing put against her voice filtered through a megaphone, Fox himself slips between speech and stylised Sprechtimme. The surface might be disarmingly simple, sometimes serene even, but there’s a deeper wisdom at play that keeps these aphoristic statements rewinding in the imagination.

—Philip Clark