Polvo's first studio album since 1997's Shapes, 2009's In Prism is a solid return to mathy form. Although 12 years is a long hiatus, it's hardly noticeable that time has passed, with the exception of a few machinery and personnel updates: trading in their el cheapo '60s Sears guitars for some new gear and swapping out their drummer. Back on Merge after re-forming in 2008 to play All Tomorrow's Parties, the bandmembers (Ash Bowie, Dave Brylawski, Steve Popson, with Cherry Valence drummer Brian Quast) still have their chops intact, and they're intent on using them to create winding guitar and bass riffs and intertwining them with haphazard shifts in tempo. Along with getting mathy and ultra-precise, the band takes the opposite approach and elongates passages, stretching songs into psychedelic space rock territory and surpassing the eight-minute mark on several occasions. As an album, In Prism may not quite live up to the explosiveness of Today's Active Lifestyles -- it's more like the calmer (and produced) Shapes. But even if it's not their best ever, it's a valid comeback that should appease longing fans.