In the very broad realm of indie-pop, there is a very fine line between twee and obnoxious. Matt & Kim have found success beyond a pretty sizable chunk of their contemporaries by straddling that line and never taking a side. It’d be easy for a band known for their hyper-energetic, relentlessly happy live show to fall into the Kimya Dawson school of slit-your-wrists-it’s-so-precocious posturing, but Mr. Johnson and Ms. Schifino have the musical chops and the genuine joie de vivre necessary to remain afloat. So it’s appropriate that Sidewalks, their third full-length, sees them expanding to a more “mature” (holy rock critic buzzword!) place without sacrificing an ounce of the bouncy, urban summertime-all-year-long power pop that got them plum slots at major festivals and placement in Bacardi commercials.

Everything about Sidewalks is bigger. The production, the instrumentation, even Johnson’s vocals, which are more assured this time around. This isn’t exactly out of the blue; go back and listen to “Cutdown” off last year’s Grand and you’ll hear the triumphant, stomping monolith of pop joy and rapture that was just waiting to burst out of them. Many of Sidewalks’ best tracks feature an expanded sound that plays to the band’s poppy sensibilities while moving toward a lusher, more fulfilled sonic palate. “Northeast,” by far the most melancholic song the duo has ever put out, using a relatively minimal arrangement of sleigh bells and ominous piano to craft what’s simultaneously a love letter and lament for their native land of New York. On both “Good For Great” and “Where You’re Coming From” they incorporate strings, a move that’s usually an easy fallback for the sake of stylistic expansion but here lends a certain gravity to the buoyancy of the tracks.

M&K are known for busting out covers of Biz Markie, Slick Rick and ODB (among others) live, and the hip-hop influence is worn on their sleeves here; first single “Cameras” incorporates tuba and stomping kick drum to create an indie version of a Dirty South brass throwdown. “Block After Block,” too, is one vocal remove away from fitting right in on an early ‘90s hip-hop station. That’s the thing about Matt and Kim; at their worst (which is rare) they’re merely an incredibly fun band to listen to. On Sidewalks, they’re something bigger; two twentysomethings from Brooklyn who’re about to explode and are going to be grinning a mile wide every step of the way.