After you've rocked all day in the sun on Saturday, cool off at night with London Calling's four-year anniversary party at the Gramophone. The night features Acid Kids (a DJ trio from Berlin) and Chicago electro-funkateers Hey Champ (Preview a song from them below.) DJ Clockwork, Nick O. and Matt Leach are also on the decks. We have two pairs of passes to give away! In the comments, leave your full name, a valid email address - and what your favorite sandwich is, and why. Contest closes at 11 a.m. Friday; winner will be notified that afternoon. Good luck!