Jamie Stewart’s ever-mutating art-pop project Xiu Xiu puts much of its focus on the bizarre juxtaposition of sounds, and with 2006’s The Air Force he created one of his most hushed yet jagged albums. “Buzz Saw” feels all the sharper thanks to the spare glints of piano and wind chimes, while the chintzy synths and deadpan delivery of “Hello from Eau Claire” (featuring vocals from Stewart’s cousin) sparkle in all their starkness.