It must mean something that the freshest indie rock boasts tunes more substantial that what is sold in the mainstream. The Shins, an unassuming quartet originally from Albuquerque, New Mexico, have not only assimilated several decades of Brit rock, chamber pop and DIY punk but have nonchalantly slipped those influences into their own intricate yet durable musical designs. On this slightly more polished successor to their 2001 debut, Oh, Inverted World, the Shins make each minute matter without strain or lapsing into fake mellowness. The band’s arrangements are concise, yet singer James Mercer’s melodies wander — calling for repeated plays — as odd lyrical phrases pop up over mutating guitars and keyboards. Getting intimate without giving away their secrets, the Shins walk a fine line between familiarity and mystery.