The transformation of Scott Walker from minor figure in ’60s pop (as the sepulchral baritone behind the Walker Brothers’ “Make It Easy on Yourself”) to reclusive avant-garde cult artist has been a strange one, so much so that some folks who saw the 2006 documentary “Scott Walker: 30 Century Man” wondered if it was a hoax. Those same people would likely consider “Bish Bosch” an endurance test, and they’d probably fail it. It’s not just that it’s larded with harsh dissonance; the compositions, arrangements, poesy, and performances come at the listener in discrete shards. For all the chaos, silence is Walker’s main weapon, with songs hitting dead stops constantly and empty voids between instruments even when they're playing simultaneously. “The Day the ‘Conducator’ Died (An Xmas Song)” has a frostbitten beauty and, not coincidentally, essentially uninterrupted momentum. For the rest, there’s less of a sense that Walker’s trying to capture the sounds in his head than that he’s trying to swat them away. (Out now) MARC HIRSH