Dream Theater had Mike Portnoy in it.
Dream Theater is an American progressive metal band formed in 1985 under the name Majesty by John Petrucci , John Myung , and Mike Portnoy while they attended Berklee College of Music in Boston , Massachusetts . Mike Portnoy . He co-produced six Dream Theater albums with guitarist John Petrucci , starting from Metropolis Pt . Besides his work with Dream Theater , Portnoy is known for his many side projects and tribute bands . In September 2010 , Portnoy announced his departure from Dream Theater after 25 years .