Detroit-bred rapper Guilty Simpson and Southern California–based producer Madlib both came of age in the early to mid-'90s, a time when rap albums were carefully constructed and often cinematic works of art. In its return to the album concept of one rapper/one producer, OJ Simpson maintains a timeless feel, even if its beats are thoroughly modern and sometimes even mind-altering. Each member of the duo helps refine the other man’s talents. The conversation peaks on “O.J. Simpson,” “New Heights,” and especially “Hood Sentence,” in which Madlib lets the musical spirits circulate around Guilty’s gruff descriptions of inner-city strife.