"Atlas, a sound cartography" is a participatory project imagined by the composers Carmine Emanuele Cella, Dimitris Kamarotos, Valerio Tricoli and the video artist Marina Gioti, open to all—children and adults alike— in Athens, Karlsruhe and Paris. We want a sound cartography of these three European cities based on sounds collected by the audience. These sounds will be used as base material for an artistic collective composition for a concert on December 13th, 2019 played live and broadcasted simultaneously in the three cities.