Launched in 2005, Harmonix’s Guitar Hero challenged players to unleash their inner rock star by following on-screen notes and strumming to the beat of popular music on a plastic guitar. Its wide appeal, licensed music, and social gameplay spawned other similar titles, including the popular Rock Band. Activision, which acquired the game’s rights, released versions of Guitar Hero for nearly every platform, including home consoles, computers, and handheld and mobile devices. The Guitar Hero series has sold more than 25 million units worldwide and more than 60 million tracks, earning more than $2 billion.