Rock Band is a series of music video games developed by Harmonix and MTV Games, and distributed by Electronic Arts for the Nintendo DS, iOS, PlayStation 2, PlayStation 3, PSP, Wii, and Xbox 360 game systems. The series, inspired by Harmonix's previous efforts on the Guitar Hero series, allows up to four players to simulate the performance of popular rock music songs by playing with controllers modeled after musical instruments. Players can play the lead guitar, bass guitar, keyboard, and drums parts to songs, as well as sing into a USB microphone. Players are scored on their ability to match scrolling musical notes while playing instruments, and by their ability to match the singer's pitch on vocals.