The Guitar Hero series (sometimes referred to as the Hero series) is a series of music video games first published in 2005 by RedOctane and Harmonix Music Systems, and distributed by Activision, in which players use a guitar-shaped peripheral to simulate the playing of lead, bass guitar and rhythm guitar across numerous rock music 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.