As he sat down behind the piano at the Hungry Brain on May 16, the 81-year-old Chicago pianist Erwin Helfer introduced himself to the 20 or so people in the club. “This is the Erwin Helfer trio — me, the piano and the stool,” he said, displaying his wry sense of humor. Helfer, who plays a free show at 7:30 p.m. every Tuesday at the Hungry Brain, 2319 W. Belmont Ave., opened his set with the classic “St. James Infirmary Blues,” before offering up a delightful sample of the various styles he has played over the decades — jazz, blues and boogie-woogie — along with charming stories and illuminating explanations of the music. Remarking on how attentive and appreciate the small audience was, Helfer said: “I’m not used to playing in places as sophisticated at this. I feel like I’m in Europe.”
