NYC rockers Shark? play indie-rock in its purest form: smart yet lackadaisical guitar-bass-drums music, sneaky-catchy and undercut with sentimental vibes. “Big Summer (Summer Ale),” from the band’s new Summer Ale EP, builds upon last year’s full-length debut Savior. It’s the prettiest thing this band has done, and it approaches epic length by this band’s standards, but it still scrapes and sputters with lo-fi charm. Spin it.