Few instrumental combinations have as much sheer sonic power as a double bass choir. The massing of low-register string voices has a particularly dramatic multiplier effect that hits bodily, producing sounds grasped as much viscerally as aurally. Composer Bertrand Denzler’s appropriately titled Low Strings leverages this formidable force in the guise of a double bass quartet, here consisting of Sébastien Beliah, Jon Heilbron, Mike Majkowski, and Derek Shirley. The composition, two versions of which appear on the album, does indeed exploit the multiplier effect of having several double basses playing long-duration tones within a tightly bound range anchored at the bottom of the instrument’s compass. Think darkly dense, dissonant harmonies and unstable sound masses thrown off by the clash of overtones, like the crashing and grinding of tectonic plates in motion deep underground.