Chan Marshall is a notoriously inconsistent performer. Over the last two decades, as Cat Power, the singer/songwriter has earned a reputation for emotional fragility that rivals her recorded output. She's been known to stop songs midway through, cry onstage, compulsively apologize and change up arrangements on the fly. But that's mostly in the past. Sun (Matador), her first LP of original material in six years, sounds both confident and upbeat; there's even some Auto-Tune. What that means for her live show has yet to be seen, but there's one thing you can count on: her show at Kool Haus on October 20 will be unpredictable.