Moving from their usual homes Subtext and Raster-Noton to the Chicago-based label Thrill Jockey, experimental electronic duo Emptyset chart new territory with their fifth album, Borders. Originally from Bristol, England, the duo of James Ginzburg (who has since relocated to Berlin, Germany) and Paul Purgas have received acclaim for their jarring, abrasive techno tracks as well as their ambitious projects involving recording inside a decommissioned nuclear power station (2013's Material) and bouncing high-frequency radio signals off the ionosphere (2015's Signal). With Borders, the duo forgoes digital processing and sequencing, instead creating music from self-built instruments, including a drum and a six-stringed object similar to a zither, as well as analog electronics used to alter and shape the sound. The duo experiments with timbre rather than melody, usually sticking to one or two notes and building up ominous drones or lapsing into stilted, lurching rhythms that struggle and occasionally seem to crash straight into the ground. Moving even further off the grid than on unhinged releases like 2013's Recur, Emptyset recorded all of the pieces on Borders live, and it feels more spontaneous than anything else they've created. The duo's recognizable heavy, fuzzy distortion is present, but there's more of a thrashing, twanging sound here. Somehow it makes perfect sense that they've ended up on the same label as Lightning Bolt, although as intense as Emptyset are, their work is significantly more restrained. On some tracks, the duo mixes the unamplified, acoustic sound of its instruments with the blown-out distortion, lending the music more of an organic, handmade feel. The music is never less than tense and bracing, but it retains a hypnotic power. Completely dispensing with the conventions of dance music and embracing techniques more in tune with natural human rhythms, Emptyset have created one of their most unique works yet.