Americans like Milford Graves, Sunny Murray, and Rashied Ali were key in freeing jazz drumming from the mundanities of timekeeping back in the 60s, but no one since–them included–has approached the kit as a pure sound generator with more glee and imagination than German percussionist Paul Lovens. For more than three decades now, he’s consistently found new ways to make instant music, applying a steely concentration to startling performances that project a childlike excitement. Lovens, who turns 50 on Sunday, has worked with just about every major improviser in both regular groups (including the Schlippenbach Trio, with Alex von Schlippenbach and Evan Parker) and countless ad hoc configurations, at once bringing a recognizable sound to any project and tailoring it to the music at hand. On his latest work, Orka (Hatology), a series of duos with Amsterdam-based American trumpeter Rajesh Mehta, for instance, he contributes his usual array of elusive clickety-clack, but also complements his partner’s tactile smears and shifting timbres with long, peeling lines scraped and bowed and rung on cymbals, bells, and the various unidentifiable metal bits that litter the floor during his live gigs. He’s one of those rare percussionists who always makes a performance better without strong-arming his cohorts, and this week he’ll work his magic with a variety of Chicago’s best improvisers. On Monday at 7 PM, he meets reedist Ken Vandermark and trombonist Jeb Bishop in a free concert at the Cultural Center’s Claudia Cassidy Theater, 78 E. Washington; 312-744-6630. On Tuesday at 7:30 PM he re-forms a trio he played with two years ago at the Empty Bottle’s jazz festival, with Vandermark and cellist Fred Lonberg-Holm, at Fassbender Gallery, 309 W. Superior; 312-951-5979. Wednesday at 9:30 PM he performs with Lonberg-Holm, bassist Kent Kessler, and visiting Italian trombonist Sebi Tramontana (who worked with Lovens on the wonderful Mario Schiano album Social Security in 1996) at the Empty Bottle, 1035 N. Western; 773-276-3600. And next Friday, June 11, at 8 PM he spars with fellow percussionist Michael Zerang and ARP wizard Jim Baker at the Renaissance Society, Cobb Hall, University of Chicago, 5811 S. Ellis; 773-702-8670. PETER MARGASAK