Dream Theater have steadily achieved a synthesis of soaring and unmistakable melody, progressive instrumentation and aggressive heaviness that has established them as peers in their genres. Through their careers they have blended technically proficient talent, ability, song writing and momentum together.

The band was originally named Majesty as John Petrucci (guitar), John Myung (bass) and Portnoy (drummer) were students at Berklee College of Music. The original band expanded quickly to include Kevin Moore (keyboards) and Chris Collins (vocals). Majesty released a demo in 1986 before Chris left the and in the same year. In late 1987 Charlie Dominici became the new vocalists and they changed their name to Dream Theater, with insipiration coming from a now demolished California movie theater.

The band relased "When Dream & Day Unite" in 1989 and it was Charilie's only album with the band. In 1991 after a search the band hired Jame LaBrie as their new vocalists. Then in 1992 the band released their second album "Images & Words". The band have jokingly since labelled "Pull Me Under" as their only 'hit', and no single has garnered the wide spread popularity that this song did.

The band line-up changed again in 1994 Moore left the band to focus on his solo projects. Derek Sherinian replaced Moore on the keyboards. Sherinian was then fired in 1999 and replaced with Jordan Rudess.

The band took a step toward its modern lineup with the addition of keyboardist Jordan Rudess, who made his recorded debut on their sixth album, Metropolis Pt. 2: Scenes from a Memory. Thanks to fan embraced releases like the dark Train of Thought (2003) and the much more diverse Octavarium (2005), Dream Theater has sold well over ten million albums worldwide, including over two million in the United States.

Dream Theater found themselves at a career crossroads following the departure of longtime drummer, co-producer and unofficial spokesman Portnoy. Through an online documentary of the audition process a new drummer was found, Mike Mangini. The personalities and individual talents possessed by Dream Theater behind the scenes were strengthened by adversity, with each rising to the challenge individually and collectively as Dream Theater pushed forward.