From Terra ICT:
O2Jam is the first online multiplayer musical game. A non-violent online game, which focused on music as its mainstream of entertainment. Here's your chance to jam with buddies of the same musical mind. A rhythm game with a twist, O2Jam is a refreshing take on the genre, because this game allows you to jam along with buddies online, from anywhere in the world. Earn money, gain experience, and buy items to customize your avatar and do battle with other people. Version 3.50 may include unspecified updates, enhancements, or bug fixes.