Dream Theater is an American progressive metal band formed in 1985 in Boston, Massachusetts. The group comprises John Petrucci (guitar), John Myung (bass), Mike Portnoy (drums), James LaBrie (vocals), and Jordan Rudess (keyboards). Petrucci and Myung are the only constant members throughout the band’s history. Portnoy was a member until 2010, when he departed and was replaced by Mike Mangini; he rejoined the band in October 2023. The band was formed under the name Majesty by Petrucci