Yes, there's enough room in today's economy for two hugely successful music games. MTV Games revealed today that Guitar Hero's rival franchise Rock Band has racked up over $1 billion in sales in North America alone in the fifteen months since it first debuted.

The $1 billion figure was based on data from The NPD Group, who also noted that Rock Band was the #1 revenue-earner across all platforms for 2008. A respectable chunk of that revenue has been from downloadable content. MTV revealed that over 40 million songs have been sold for Rock Band since November 2007. There's currently 614 songs from 269 bands/artists available through Rock Band discs and the online music store.

In addition to earning gobs of money, developer Harmonix has received its share of accolades as well. At last night's Game Developers Choice Awards, studio co-founders Alex Rigopulos and Eran Egozy received the Pioneer Award because of the innovations they introduced in Rock Band and the first two Guitar Hero games.