Rock Band Track Packs (called Song Packs in Europe) are a series of supplemental media discs for the Rock Band series of music video games. The packs are developed by Harmonix Music Systems and Demiurge Studios (earlier packs were developed with Pi Studios), and distributed by MTV Games and Electronic Arts. Harmonix has announced they will release additional discs, containing new songs not in the original release that have been made available through downloadable content. The track packs are fully functional stand alone games and do not require separate Rock Band titles to play. However, on consoles that support downloadable content, the songs from these packs can be integrated with other Rock Band titles.