Aesop Rock's legendary Greek namesake wrote fables with morals like "A man is known by the company he keeps." And Aesop the MC (a.k.a. New Yorker Ian Bavitz) has borne out that bit of ancient wisdom: Since 2001's acclaimed Labor Days, he's been a mainstay of Def Jux, the underground hip-hop powerhouse whose prevailing aesthetic -- dense sounds and even more densely packed verses -- has been a perfect match for his own surrealistic rhymes. In case you've had trouble deciphering any of them, Aesop's latest release (the seven-track EP Fast Cars, Danger, Fire and Knives) came packaged with a lyric book that gathered his greatest hits in written form. But it was the sound of Fast Cars, as much as the writing, that was revelatory: Teamed once again with his old producer-pal Blockhead, Aesop came up with his catchiest and most direct collection yet, sounding chipper enough to court a new danger not name-checked by the EP title: mainstream acceptance.