San Francisco MC Aesop Rock has long been the acknowledged king of hipster-hop, bringing to the game a cerebral, often ironic lyrical sensibility and a taste for adventurous production. Long Island-born AR (born Ian Bavitz) has a lifetime of personal issues and sociopolitical preoccupations banging around in his brain, and he continues to air them on None Shall Pass, his fifth full-length release. Aesop's knack for getting polysyllabic while maintaining an organic flow is in full effect here: how many other rappers can make ''Helvetica'' and ''euthanasia'' fall trippingly off the tongue? Backing it all up with tracks that mix '70s funk, IDM-style electronica, left-field psychedelia, and classic West Coast beats, Aesop Rock (with guest shots from pals El-P and the Mountain Goats' John Darnielle) proves that there are still fresh approaches available to rappers with a searching spirit.