Kind curators that they are, the fine folks behind the Unsound Festival have an event that’s kind even to the emptiest of wallets. At noon on Saturday, February 6th, the experimental German trio Groupshow (known separately as Jan Jelinek, Andrew Pekler and Hanno Leichtmann) will perform an 8 hour long improvised piece to accompany Andy Warhol’s film, “Empire.” The event takes place at Le Poisson Rouge (158 Bleecker St.) and is completely free. For a hint as to what you can expect from this massive undertaking, check out “Pet Hair Magnet,” generously made available by Groupshow.