As serendipitous or profound as improvised music can be, it’s not always the most scintillating thing to watch. That’s why a live show by Dutch sound artist Jaap Blonk–an extreme vocal acrobat who takes great pride in the strange expressions he can twist from his singular mug while he’s performing–is a treat. (Check out the hilarious interactive “Blonk-Organ” page on his Web site, www.bajazzo.com/blonkorgan.html, for some excellent thumbnail representations of what he does.) Blonk can in no way be called a singer, but his precise control of the astonishing variety of utterances that fly, ooze, pop, and drip from his contorted lips make him a first-rate improviser. His work in the rock-leaning trio Braaxtaal captures him at his most theatrical and bombastic, but he can temper his attack for a more spontaneous setting without sacrificing any of its impact. Blonk will appear in a number of different contexts over the next two weeks in Chicago. On Sunday he performs at the Empty Bottle Festival of Jazz & Improvised Music with the collaborators who played on his most subdued recording, a contribution to the Kontrans “Improvisors” series, in 1996: Swedish reedist Mats Gustafsson and percussionist Michael Zerang. On Wednesday he performs with Zerang and cellist Fred Lonberg-Holm, with whom he made the recently released First Meetings (Buzz); the album cleverly blurs the distinctions between his unhinged sputtering and Lonberg-Holm’s tactile scrapes. Next Friday Blonk performs solo and in a duo with trombonist Jeb Bishop, whose slinky, almost vocal eruptions should make a swell match; and finally, next Saturday, he’ll team up with keyboardist Jim Baker, using electronics to alter his voice. Sunday, 5 PM, Empty Bottle, 1035 N. Western; 773-276-3600. Wednesday, 8 PM, HotHouse, 31 E. Balbo; 312-362-9707. Next Friday and Saturday, May 21 and 22, 8 PM, Link’s Hall, 3435 N. Sheffield; 773-281-0824. PETER MARGASAK

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