Fans of Vampire Weekend may want to pick up a copy of the Metro Thursday. The band, which headlined last weekend’s Boston Calling show on City Hall Plaza, guest edited today’s edition of the newspaper in Boston, New York, and Philadelphia. What does that mean exactly? Metro features editor Pat Healy told us he met with Ezra Koenig, Rostam Batmanglij, Chris Baio, and Chris Tomson in New York to “brainstorm some topics” for the paper. Some, like Koenig’s idea to write about all of the fashion designers from the Bronx, didn’t fly. But others, like Batmanglij’s pitch to report on genetically modified food, did. If the story’s no good, what’s the harm? The paper is free.