Gelb, the mystical master of the shakuhachi, has joined forces with three kindred spirits to produce music that uses dynamics, space, spontaneity, and a high level of intercommunication to convey a very personal message. With Oliveros fingering intriguing staccato accordion outbursts, Reason probing deeply into the piano’s core, and German bass aficionado Phillips exploring the fullest range of his instrument, the quartet holds forth with a session that rewards those who adhere to Oliveros’s thesis on listening. She is an exponent and teacher of ‘Deep Listening,’ a concept that promotes “exploring the relationship among many and all sounds.” The music by this quartet is a perfect vehicle for developing those concepts. Each musician produces music that is the combined product of his or her own inventive skills and the resounding motivational vibes that are transmitted by the other three. Gelb may inject freely floating, high-pitched tones, which are then absorbed and recast into a compatible sound language by the others using their own imaginativeness. Oliveros intermittently massages emotional levels of pure sound or the sound of air, Reason adds gentle and then violent stabs of diversity along with intricate harping of the piano strings, and Phillips goes either the arco or pizzicato route with angular lines of density. They hear each other and respond accordingly. Although the origin of the shakuhachi is Japanese, the music of the quartet is very much Western in design and execution. Gelb tames his instrument to yield mesmerizing otherworldly improvisations. Oliveros is able to make her accordion sing with sadness or joyousness, unleashing the sonic extremes of the instrument at essential moments or resorting to tranquilizing quietude. Reason defines color with a wide palette of ever-changing hues that seeps into the crevices of the songs, while Phillips often shows a tyrannical side with heavy bass eruptions to bind the music solidly. As a unit, they speak in a broken tongue of rarified beauty that is demanding but fully rewarding. Doing as Oliveros suggests will provide the key to unlock this fascinating language.