Recording as Grouper, Liz Harris has been alchemising ethereal and enigmatic albums for over 13 years, combining her gossamer voice and sparse instrumentation with seemingly bottomless layers of tape hiss and static to craft richly detailed and emotionally resonant worlds of sound. With her latest release, Grid of Points, Harris’ spartan musical palette has been pared back even further, dispensing with the looped guitars and fuzzed out atmospherics of her earlier albums to create a pristine and glacial piano and voice record filled with space and extended moments of silence. In lesser hands, the album’s extreme economy of sounds could…