If their debut birthed an infectious synthesis of supposedly opposed styles, New York quartet Vampire Weekend’s second album dares to take things even further. Nothing, musically speaking, is off the table, be it the riptide of surf guitar at the heart of “Cousins” or the woozy Caribbean skank that accompanies Ezra Koenig on “Diplomat’s Son.” Wider in scope but still as pristine as a brand-new button-down, Contra manages to be poppy, opaque, and, yes, thrillingly contradictory.