Essex Foam Party sees Grutronic, a free improvising collective, join forces with guests vibraphonist Orphy Robinson and sampler Paul Obermayer. Mixed among the moist pulses and triggered cross textures that characterize much of the music are interludes of keyboard comping and runs from Stephen Grew, and of hollow thumps and percussive power from David Ross. Meanwhile, Richard Scott’s synthesizer, samplers, and Buchla lightning, plus Nick Grew’s processing and transduction, explore the interface displayed through watery pulsations, stop-time slides and gong-like input-output—among other sound extensions. Yet the refusal to completely surrender to electronics is intensified on the three longest tracks when Robinson’s vibraphone licks and rebounds. The electronic-manipulation skills of the original Grutronic players are such that there’s little overt sonic divergence between the quartet’s Ball Pool Blues and the sextet’s Madness and Civilization. Overall the timbral mashup among acoustic, processed, and sampled timbres intensifies the individual instrumental sounds as much as it alters them. The results demarcate Grutronic’s sonic solutions as they define the group’s individual personality.