Alice Cooper pioneered the violently theatrical brand of heavy metal that would be called shock rock. While Cooper perfected a vaudevillian approach to shock rock, Ozzy Osbourne took the form to darker places reaching a crescendo in the biting off of a live bat's head on stage. In the early 1990s, a group of artists including Marilyn Manson, Nine Inch Nails, My Life With Thrill Kill Kult, Ministry, KMFDM and Rob Zombie used keyboards and industrial music to push shock rock into a new era. Explorations between good and evil or beauty and the grotesque ensued.