Godspeed You Black Emperor! follows in the footsteps of Roy Montgomery, Holger Czukay, and Scenic by composing vivid sound tracks to nonexistent movies. But while those other artists seem content to let their records do the talking, this nine-piece ensemble from Montreal devotes most of its energy to its live show: in its four years the band has embarked on several tours but made just one album, f#a#°, originally released in Quebec on vinyl and only recently reissued on CD by Chicago’s Kranky label. Each of the record’s epic suites opens with apocalyptic poetry or the paranoid ramblings of a street person, which gives way to collages of sonic textures–a segment of distorted tape loops, for instance, followed by rustic slide guitars, keening bagpipes, or melancholy strings–and longer passages of massed, twanging spaghetti-western guitars that intertwine over relentlessly building martial rhythms. In concert the group wisely ditches the spoken intros, digging in with a ferocity only hinted at on the disc and underlining the music’s cinematic scope with flickering film loops. Godspeed You Black Emperor! opens for Low. Saturday, 10 PM, Schubas, 3159 N. Southport; 773-525-2508. BILL MEYER