Probably the world's best-known player of the kamancheh--a gourd-shaped fiddle held vertically, with the bottom resting on the ground or on the player's knee--Tehran native Kayhan Kalhor has done some of the obligatory world-musician-made-good stuff, collaborating with Yo-Yo Ma's Silk Road Ensemble and composing for the Kronos Quartet. A skilled musician and a sensitive composer, he's certainly up for anything. But for my money he's best as a sort of Paganini of Persian classical music. I first heard him play live several years ago at the Old Town School with his Persian-Indian fusion ensemble Ghazal and was mesmerized by the way every rasp and hiss and breath of his bow carried meaning. Not for him the cloying tones of some Western classical violin: the kamancheh as he plays it transforms the stinging, wind-flung dust of history into something that purifies the vision. For this free concert of improvisations, Kalhor will present his new five-piece ensemble of traditional woodwinds, strings, and percussion; this is the group's Chicago debut. Wednesday, April 28, 7 PM, Preston Bradley Hall, Chicago Cultural Center, 78 E. Washington; 312-744-6630.