Though they say it's a rule, a show that comes in threes is rarely a good thing. This, however, is a killer lineup. Sonic Youth: self-explanatory. Wild Flag: Carrie Brownstein and Janet Weiss’ (of Sleater-Kinney) new psych-rock outfit. Kurt Vile: we still can’t stop listening to Smoke Ring for My Halo. Each of these guys could be playing shows with solid opening acts respectively, but together they’re a trifecta spanning three decades of things we actively like; a three-part showcase of old and new indie-rock classics.