|Origin||Long Island, New York|
|Genres||Progressive rock, progressive metal|
|Labels||Roadrunner, Warner Bros., Atlantic, Elektra, EastWest, Atco, Mechanic|
|Past members||Mike Portnoy|
- James LaBrie (vocals)
- John Myung (electric basses)
- John Petrucci (guitar)
- Jordan Rudess (keyboards)
- Mike Mangini (drums)
The band was founded by John Myung, John Petrucci and Mike Portnoy. Myung and Petrucci are the only original members that are still in the band today. They changed their singer twice in the late 1980s when Chris Collins was replaced by Charles Dominici in 1987. Dominici left the band only three years later, in 1990, and James LaBrie joined and stayed until today. Dream Theater's keyboardist also changed three times. Kevin Moore played with the band from 1986 until 1995 when he left and Derek Sherinan took his position until 1999. Jordan Rudess is Dream Theater's Keyboardist now. He is known for his excellent technique and compositional skills. In September 2010, drummer Mike Portnoy left Dream Theater, and was replaced by Mike Mangini.
The members of Dream Theater are known for having excellent playing technique of their instruments, and for their songwriting. Their music is very complex and the songs are often long, their longest being Six Degrees of Inner Turbulence at 42 minutes in length.
Their songs contain a lot of instrumental sections, in which no vocals are heard and only the instruments play (these parts are called "instrumental passages") and also many solos. Another feature of their music is that during each song, the speed often changes, and occasionally style changes too.
They once said that other bands have trouble making long songs. They said they have trouble making "short" songs. Most of Dream Theater's music is very difficult to play because of the high speed it has to be played with and the complex rhythm.
- When Dream and Day Unite (1989)
- Images and Words (1992)
- Awake (1994)
- Falling into Infinity (1997)
- Train of Thought (2003)
- Octavarium (2005)
- Systematic Chaos (2007)
- Black Clouds & Silver Linings (2009)
- A Dramatic Turn of Events (2011)
- Dream Theater (2013)
- The Astonishing (2016)
- Distance Over Time (2019)