The computational power and sensory capabilities of mobile devices are increasing dramatically these days, rendering them suitable for real-time sound synthesis and various musical expressions. In this paper, we demonstrate a novel mobile music making system which leverages the ubiquity, ultra-mobility, and multi-modality of mobile devices (iPod touch) for people to create and compose music collaboratively. Unlike the conventional music making applications which generate the music on a single mobile device with a preset sound and interface, our system allows several players in a group to be connected together through wireless LAN network, creating music with different sounds and interfaces. While playing, the music of all the players can be sent to and mixed on each individual device so that each player can hear all the players’ music through his own device. Moreover, players may configure their musical interfaces with different difficulty levels, starting notes, scales and displ...