BLACK HIPPY: All four members of this frantically creative L.A. rap collective are worth your attention: Ascendant and frighteningly talented syllable-splitter Kendrick Lamar, playfully thoughtful gangster Schoolboy Q, incisive tough guy Jay Rock, libertine weirdo Ab-Soul. Performing together and separately all over the place this week, they could run SXSW the way Odd Future did last year.