There's something liberating about not knowing what the hell Gustav Ejstes is singing on his eight albums as Dungen. (Unless you speak Swedish, in which case bully for you.) The cosmic effect — bolstered by the seemingly freeform, actually methodical instrumentation and arrangements, like Jethro Tull pied-piping at the gates of a Sun Ra dawn — is so powerful that it's tempting not to peek behind the curtain. But let's. This game got off to a rocky start when the first two Google translations, for Dungen (pronounced dune-yen) and Skit i Allt (the band's 2010 album), came back as "fertilize" and "shit in everything." Surely, if Ejstes was some kind of feces fetishist, it would've been reported on by someone in the past 15 years. Digging deeper: "Skit i allt" is colloquial for "screw it all," which certainly fits with the LP's conventions-be-damned spirit, and fertile isn't a bad place to start in conceptualizing the nutrient-rich Swedish soil from which Dungen sprung. Allas Sak (Mexican Summer), its first record in five years, means "everyone's thing," and it should be, a mystical journey in and out of tightly sculpted psych/pop and narcotic prog-fog — with song titles ranging from the usual ("Flickor och Pojkar": "Girls and Boys") to the appropriately trippy ("Ljus In I Min Panna": "Light Into My Forehead") to the outright bizarre ("Franks Kaktus": yes, "Frank Cactus"). Perhaps we should just listen to Dungen's 2004 breakout Ta Det Lugnt and take it easy. Everyone's favorite New Orleans noisemaker Caddywhompus opens. Tickets $16 in advance, $18 at the door.