Guitar Hero is a series of music rhythm game video games first released in 2005, in which players use a guitar-shaped game controller to simulate playing lead, bass guitar, and rhythm guitar across numerous rock songs. Players match notes that scroll on-screen to colored fret buttons on the controller, strumming the controller in time to the music in order to score points, and keep the virtual audience excited. The games attempt to mimic many features of playing a real guitar, including the use of fast-fingering hammer-ons and pull-offs and the use of the whammy bar to alter the pitch of notes.