“You don’t want everything to be perfect,” Sherman Irby has said. “That’s the purpose of dissonance.” Unfortunately, we’ve come to expect anything but that kind of statement from musicians like Irby–he’s a thirtysomething mainstream alto man, raised in the south, whose formative years coincided with the rise of Wynton Marsalis’s reactionary vision of jazz. But Irby’s iconoclasm is more than just talk: he has the technical fluency, emotional ballast, and venturesome spirit to challenge the party line. On his lively second album, last year’s Big Mama’s Biscuits (Blue Note), his tone sounds sweet at first, but soon reveals patchwork undertones that give it unusual depth. Low, guttural growls, along with the split high notes that punctuate his steeplechase solos, demonstrate what he means about the purpose of dissonance; the pianoless trio format he uses on most of the disc further underlines his willingness to push the mainstream envelope. Since too many young altoists still model their styles on Charlie Parker, or on even earlier saxists, I hesitate to point out how much Irby reminds me of Parker’s most accomplished successor, Cannonball Adderley–right down to his burly build. But Adderley’s late successes came from breaking his own mold–as the social climate of the 60s grew more strained and painful, his tone grew more strident and his improvisations shook their tether–and that’s the Adderley who seems to have captured Irby’s attention. Irby has no qualms about playing pretty or about slip-sliding into sounds equally gritty, often within the same four-bar phrase. And though like Adderley he’s still driven by the blues, his trio veers close enough to AACM bands like the Ritual Trio and the New Horizons Ensemble to tap them on their shoulders and ask for further directions. The rest of the trio comprises bassist Gerald Cannon and drummer Willie Jones. Wednesday, 8 PM, Bennett-Gordon Hall, Ravinia Festival, Green Bay and Lake Cook Rds., Highland Park; 847-266-5100. Thursday, 7:30 PM, Buntrock Hall, Symphony Center, 220 S. Michigan; 312-294-3000 or 800-223-7114. NEIL TESSER

Art accompanying story in printed newspaper (not available in this archive): photo/Alan Nahigian.