High Quality Content by WIKIPEDIA articles! Stephen Gregory Bier Jr., formerly known by his stage name Madonna Wayne Gacy (born March 6, 1964, Fort Lauderdale, Florida) is the former keyboard player for Marilyn Manson, 1989-2007. His stage name came from the names of the singer Madonna and the serial killer John Wayne Gacy. He has also been referred to as Pogo (John Wayne Gacy`s clown name).