By 2007, Aesop Rock was a decade into a career that had firmly established him as one of rap’s unreplicable auteurs, an artist who could be bitten only insofar as he could be understood. And still, when he sat down to write hisfifth full-length album, None Shall Pass, relics of his earliest work kept popping back up: the sorrow and salvation that can each be found in rigid structures, the horror of the ordinary, the tyranny of routine. Over a series of beats constructed in near-total by himself and Blockhead (El-P furnishes one track and co-produces another; Aes’ friend Rob Sonic handles the digital-gothic “Dark Heart News”), None Shall Pass argues for Aes as the chief correspondent of an American decline so smooth that it often felt comfortable.