With shadowy beats from Madlib and the late J Dilla, plus dense rhymes about Darwin and a rough Brooklyn upbringing, Mos Def's fourth solo album is both mildly strange and a clear step up from his dismally undercooked 2007 record, True Magic. The rapper-actor doesn't maintain quality control during the course of 16 often arty tracks. But you could make a solid mix from Ecstatic's best moments,...