Best known as the revolutionarily skilled drummer for archetypal psych-blues power trio Cream, Ginger Baker may be the most toxically nasty musician ever. A demonic tornado behind the kit who was the only Caucasian to infiltrate Afrobeat pioneer Fela Kuti’s ensemble, Baker inevitably alienated his bandmates, wives, and children—everyone except his polo horses. Jay Bulger’s doc captures Baker’s violent childhood, itinerant existence, financial and inter-band disasters, bitter personality, and dazzling musical gifts in a cancerous-warts-and-all manner. (Grand Illusion, 1403 NE 50th St,, 7 pm, $8)