See, back in 1995, two college buddies from MIT – Alex Rigopulos and Eran Egozy – founded Harmonix, and it was their goal to bring the world of popular music into the growing world of video games. They brought us Frequency, Karaoke Revolution, Guitar Hero (initially) and the most recent, Rock Band franchise. The latter has proven quite lucrative: according to GameSpot, Viacom (owner of Harmonix parent company MTV Games) has revealed that both Rock Band and Rock Band 2 have now wold 7 million units in 13 different countries worldwide. Said Viacom president Philippe Dauman- "We have a tiger by the tail in Rock Band and our growing games business." All this, and the PlayStation 3 version of Rock Band 2 wasn't included in these figures, as it just released last month. Overall, the two games have generated nearly $574 million in U.S. retailers alone, and this doesn't include any revenue from the new Rock Band music store, which allows gamers to purchase single songs and track packs for the games.