Guitar Hero is a series of rhythm video games published by Activision in which players use guitar-shaped controllers to mimic the playing of numerous popular rock music songs in a score attack gameplay; later games in the series have included support for both drums and vocals and playing as a full band. With over $2 billion in total sales worldwide, the game series has made a significant cultural impact, becoming a "cultural phenomenon" and recognizable in the popular culture. The series has been found to influence younger players into learning real instruments and has found application within the health care industry to help recovering patients.