Oftentimes when members leave bands there’s a certain degree of animosity that would make such an idea an impossiblity, but when guitarist Ben Greenberg (now with The Men) and drummer Ian Antonio departed Brooklyn-based avant-jazz/ noise ensemble Zs last year, it was under amicable enough terms to allow a pretty interesting concept to come to fruition: new LP Grain comprises the last recordings of the previous line-up, as manipulated, processed, chopped, screwed and generally remixed into oblivion by their replacements. Split into two 20-minute movements – the first constructed by new guitarist Patrick Higgins (a composer for strings who also arranges Bach for guitar) and the only constant throughout the band’s many different incarnations, saxaphonist Sam Hillmer; the second by new drummer Greg Fox (Man Forever, Guardian Alien) – Grain initially bears scant resemblance to its 2010 predecessor New Slaves, but listen hard enough and you can hear echoes of that album’s punk-jazz skronk under the loops and layers of digi-noise. Guitar harmonics clang like church bells, whilst Hillmer’s sax is tweaked to sound like strings, or a car alarm, or an injured animal crying; mystery percussive objects and electronics blend together, generating gentle rhythmic pulses and shuddering jolts as micro-processed synths and sampled drum-rolls ricochet violently around the stereo field. With its lengthy passages of droning ambience and – in particular – Fox’s kaleidoscopic glitch-hop treatments on “Part 2” (an excerpt of which is below, accompanied by video the drummer shot during a bullet train ride from Tokyo to Osaka), Grain marks a new chapter in a decade-long story whose narrative – lurching from academic composition to downtown free-jazz to experiments with electro-acoustic noise and beyond – remains undefined. An artfully blurred snapshot of group in a perpetual state of transition, Grain is out April 30 via Northern Spy Records.