From the first seconds of the swaggering shuffle “Deep Pockets” to the thundering closing note of the bookending “Brother Steve,” Boston veteran Katz and band demonstrate their unusual split-personality mastery of jazz and blues. And not just soul-jazz, either, but real, thorny jazz as in Charles Mingus’ “Better Get It In Your Soul,” where Katz and company find the warped waltz deep inside the gutbucket and flash chops that go way beyond the usual organ-blues workout. Download: “Ice Cream Man.”