RedOctane's follow-up to the critically acclaimed rhythm game. Guitar Hero II features a brand-new and expanded track list, more venues and new play modes, and aims to rock longer and harder than its predecessor. RedOctane has once again teamed up with veteran music game developer Harmonix for the sequel, and is using famed recording studio WaveGroup for its music production, who also recorded the covers for the licensed tracks in the original Guitar Hero. The game's all-important track list encompasses all forms of rock and metal music including classic rock, "hair metal", heavy metal, modern rock and alternative rock. In total, Guitar Hero II features more than 55 songs. New modes include a multiplayer co-op mode where players can play not only the lead guitar track, but rhythm or bass as well, allowing players to take on two different sections of the song simultaneously.