Play an Aesop Rock song straight through, or start in the middle and listen to the first half later, and it'll make the same amount of sense. Rock's new album, None Shall Pass, works the same way. This hour of hip-hop defines itself as a mess of parts: Rock's speed-shifting delivery, lyrics that deliberately tangle, the jumble of rich instrumentals and detached voices he and his partner Blockhead bring to production. Though geeky as ever, Rock seldom lets himself sound friendly. The title track comes closest, keeping empathy just an inch ahead of the wordplay. ("I will remember your name and face on the day you were judged by the funhouse cast.") "39 Thieves" and "No City" come loaded with plodding vocals and dramatic snippets that threaten to turn fun into ostentation—the last thing a rapper this intelligent needs. Aesop is so comfortable in so many places that everywhere he goes will sound a bit like the middle ground. But whatever the hell it is, None Shall Pass builds on challenges and pleasures that middling hip-hop doesn't have room for.