Harry and the Potters Make It Safe for Nerds to Rock AgainWhen wizard rock band Harry and the Potters bounded out onto the stage in front of the Brooklyn Public Library Saturday afternoon, dressed in their prep-school uniforms, and asked their audience of mostly teen- and tween-agers (and their parents) to join them in the recitation of the pledge of allegiance, you might have been forgiven for thinking that you had stumbled into some kind of school assembly.