Sometimes a musical duo defies genrefication. Elliot Sharp and Janet Feder, who perform Saturday, November 12, at St. Cajetan's on the Auraria campus, explore avant-garde, free jazz, folk, world music, noise and classically informed territories -- all while maintaining the laid-back aura of a casual conversation. Neat trick. Although this special occasion marks multi-instrumentalist Sharp's first-ever Colorado appearance (active in New York's experimental scene, he's collaborated with every heavy hitter from the Kronos Quartet to John Zorn), Feder remains better known throughout the Front Range for her beguiling compositions on prepared acoustic guitar. Attaching wires, beads, roach clips and other resonating objects to her six-string or dobro, the Denver-based finger-style virtuoso simulates the sound of bells, gongs, marimbas and rattles. The combination of Feder's sonic equations and Sharp's highly rhythmic finger-tapping patterns (and ingenious laptop programs) makes chaos theory seem fun and effortless. Forget about what to call it: Just sit back and enjoy the ride.