Side A is a very static, strong drone; recorded live in October 2011. Constructed out of several layers of tones and hums, it pursues a straight line more-or-less until its end. Zeh tweaks his materials very subtly, with his main techniques pulling them in two quite different directions. The first of these is towards beating tones and throbbing pulses; the piece begins with a gently throbbing low end, and throughout the track these modulations rise and fall - though never with any overwhelming strength (thus maintaining the tension of the drone). The second direction goes the opposite way entirely: rather then playing layers against each other, Zeh somehow coaxes singing tones from them. Thus, tibetan bowl-like drones emerge from the main body of sound; before diminishing, and returning. The piece ends with the sounds of tape reels, amplified by contact mics; these rather decrepit rhythms carry the track to its close, with Zeh creating a nice stereo-bouncing effect.

The second side of the tape, according to Zeh’s inlay notes, was created by subjecting recordings of electromagnetic fields to a “variety of tape-based processes of manipulation.” The track begins, perhaps unpromisingly, with the sound of slurring tape - and then Zeh brilliantly grinds this sound into the ground. He doubles it, layers it; makes it resonate and reverberate - it really is a masterful piece of work. In terms of what’s actually occurring, you might imagine (at the most basic level) someone manipulating a loop; but perhaps a more helpful notion is someone like John Butcher constantly producing a very short passage on the sax (trilling, even), with equally constant variations of tone, timbre and melody. There’s a relentless, vigorous exploration of the initial slurring sound - in fact, Evan Parker would be the more obvious saxophone parallel, given his spiralling repetitions. Zeh teases out all kinds of colour, making the track growl and vibrate; building it into buzzing maelstrom with malevolent traces, before it decays down into a warbling drone. After this, Zeh breaks it further; till the listener is left with scratchy, hesitant whines and murky rumbles, slowly playing out in an ocean of tape hiss. Its quite mesmeric.

Whilst the first side of “Polarity” is undeniably competent and enjoyable, it’s the reverse offering that truly makes a name for Jason Zeh. There are a few projects that properly explore the use of tapes and tape machines - rather then simply using recorded sounds on tape as source material - and it’s sometimes an area that produces rather austere works, given the limitations of the “instruments”. “Polarity”, though, shows Zeh to be capable of creating great colour, from the barest of sounds. I’m loathe to saddle him with the burden of “the acousmatic Evan Parker”, but in case his future reveals that: you heard it here first.