Alvin Lucier's music is a thing of icy calm and crystalline beauty somehow detached from histrionics, despite the intense involvement of its participants. Nowhere is this dichotomy more evident than in this two-disc set of recent compositions involving mainly acoustic instruments (the exception being the title track, composed in 2001, a piece for five flutes – played by one player – and two pure-wave slow-sweep oscillators). Two of them, Twonings (2006) and Broken Line (2006), explore the changing rhythmic beats formed when two instruments approach unisons. It's a concept Lucier's been examining since the early 1980s, and each instrumental combination is revelatory. The excellence of the performances is established from the opening notes of Twonings, performed by pianist Joseph Kubera and cellist Charles Curtis, whose gorgeous sostenuto brings back memories of his double-disc Lucier compendium of similar scope on Antiopic a few years ago. Indeed, whether they involve conflicting tuning systems or approached and ultimately achieved unisons, all three beat pieces receive finely crafted performances, with Broken Line especially noteworthy for flutist Robert Dick's use of a mouthpiece capable of glissandi. Almost New York, the other flute study here, is performed by its dedicatee Carin Levine, and once more the recording captures stunning detail, filling the soundstage as she moves between instruments.

The odd man out, as it were, is the expansive Coda Variations (2005), written for six-valve tuba in just intonation. Occupying the entire second disc, it shares length and austerity with the work of Morton Feldman, to whom it is an homage. Robin Hayward's performance renders the piece as much a study in timbre as in tuning, and as the work wends its nearly motionless way from note to note, each successive pitch sounds richer and fuller, a whole Webernian universe with each breath.–MM, Paris Transatlantic