Birmingham Contemporary Music Group

Adrian Boult Hall, Birmingham

Los Angeles-born David Lang may be co-founder of New York's "Bang on a Can" New Music Festival, but there were no bangs and few cans in his mesmerising new 40-minute piece, The Passing Measures, newly commissioned by the (BCMG) and Birmingham Jazz within their groundbreaking programme entitled The Series.

Bold risks are what makes BCMG thrive. The Series is gorgeously unpredictable; one never knows what to expect next. Lang's new work invites a "minimalist" tag, though without any implied detraction. It's a prolonged reverie, "dreamy and seamless", with long-sustained chordings evincing their own unaccented slow passage of time. Its texturing forms part of the interest: a string section of eight cellos alone, largely in unison; a full complement of brass, sustaining muted chordings with a pair of keyboards in lightly percussive support. Whispering percussion - subtly scraped brake drum, periodically stroked gongs, the occasional glimpse of muted tympani - lends a mysterious, almost reverential undertow.

Set against this hinterland, but integrated so as to form part of it, are solo bass clarinet, a supporting line of disparately tuned double basses and clear but unostentatious electric bass guitar. This bass line's dogged avoidance of root position helps lend the piece its questing, never settling demeanour.

And meshed within all this, not so much a vocal distraction as a part of the orchestral fibre, are eight low-pitched female voices, whose wordless chordings add to the soft ebb and flow and lend an oddly disembodied, slightly syncopated feel to the relaxed, unrelentless onward movement.

What was the result of all this? A strangely appealing canvas, a curiously untedious continuum, by turns melancholic and optimistic - first Debussian nocturne, then striving for a tantalisingly elusive goal like the distant, unresolved echo of a Bruckner or Mahler adagio, or yearning, like some wafting Delian mantra or (latterly) secularised orthordox prayer.

Odd signposts shimmer and gleam within the mobile textures: a marked harmonic shift in the double basses, some soft interpellation by muted trumpets or a clutch of implied, but unresolved, dominant sevenths harped on in the solo clarinet line (all instruments are marked pp, and very subtly amplified). The whole amounts to suggestion rather than statement, neither assertive nor ecstatic, a kind of evocative Monet that tantalises for as long as you choose to gaze upon it. The performance - immensely demanding on all forces - was impeccable.

Marty Ehrlich was the appealing soloist, and, in a well contrasted first half, his jazz trio excelled. Some three-part writing verged on the routine, but the solo and dialogue writing entranced. Mark Dresser's vivid double stopping, eerie harmonics and guitar-like pizzicato on double bass furnished a marked high point of the evening.