Those initials stand for (Thomas) Lehn, (Carl Ludwig) Hübsch, (Philip) Zoubek and (Franz) Hautzinger, who joined the already existing trio in this recording from 2008. The instruments they play are, respectively, analogue synthesizer, tuba, piano and quarter-tone trumpet with delay. The opening “Zoom” is characterized by hovering images and sparse definition, shadows prevailing upon light throughout. The title track opens with a sudden increase in contrast and dynamic interaction, with Zoubek acting as a semi-tuned percussionist of sorts while Hübsch and Hautzinger launch abstract imprecations and Lehn furnishes the room with his classic mix of biotic pulses and persistently mutating shapes. Rare moments of calm betray a lingering sense of mild acrimony between the physical components of the sounds, ultimately flowing into clamorous pandemonium followed by inauspicious echoing arcs and subaqueous gases. “Lens” begins with adjacent pitches producing Lucier-like beating effects, which are immediately scarred by bizarre synth noises and bouncing thuds before we enter a low-frequency zone, all muffled grunts and moans enriched by bowed metals and howling self-doubt. “Hal” adds enigmas and disagreements, concluding this brilliant(ly undefinable) record with off-kilter plinks and plonks, spikes, bumps and tiny farts. This is improvisation as it always should be: intelligent and unpredictable.