From DCist contributor Catherine Andrews: Hopelessly cynical hipster kids can get a dose of feel-good, irony-free music tonight with the Polyphonic Spree concert, going on at the 9:30 Club (815 V St. NW). Twenty-five bandmates, dressed in technicolor floor-length robes, indoctrinate audience members into their wonderful world of musical puppies and rainbows. The Texas-based group, building on the success of their first album, “The Beginning Stages of …”, has found some critical success with…