CitySonar is an experiment in using geographical information to create sound.
Choose a feature (such as 'cafe'), and they will appear on the map. Press play, and the locations of the cafes will be used to create notes which will start to play. The closer to the centre, the higher the note will be, and the order is determined by a clockwise sweep from the centre of your viewport. Additional features can be added to the same map to create more sounds.