Oakland’s Tower of Power make hot, funky soul, with nods to James Brown’s strutting R&B and to flowery California sunshine pop. Their greatest years include the rump-shaking “What Is Hip?,” the aching “You’re Still a Young Man,” and the politically charged “Only So Much Oil in the Ground.” Lenny Williams shines on the wintry ballad “So Very Hard to Go,” while Rick Stevens commands the toe-tapping funk of “Down to the Nightclub.” Throughout, the famed Tower of Power horn section is a constant.