As if to test the robustness of their longstanding modus operandi – intensely sad, often sublime songs that proceed at the pace of a funeral procession – Minnesotan trio Low enlisted Katy Perry producer Matt Beckley for their 2011 album C'Mon, with reassuringly desolate results. Wilco's Jeff Tweedy presides over their 10th album, and what variations are introduced here – swelling piano chords on So Blue, searing lead guitar largely replaced by acoustics – remain subject to the constraints of the band's sonic asceticism. As ever, it's the gorgeous harmonies of husband and wife Alan Sparhawk and Mimi Parker that make these sparsely decorated songs take flight.