Dream Theater is an American progressive metal and progressive rock band formed in 1985 under the name Majesty by John Petrucci, John Myung, and Mike Portnoy while they attended Berklee College of Music in Massachusetts. They subsequently dropped out of their studies to concentrate further on the band that would ultimately become Dream Theater. Though a number of lineup changes followed, the three original members remained together along with James LaBrie and Jordan Rudess until September 8, 2010 when Portnoy left the band. In October 2010, the band held auditions for a drummer to replace Portnoy. Mike Mangini was announced as the new permanent drummer on April 29, 2011.
The band is well known for the technical proficiency of its instrumentalists, who have won many awards from music instruction magazines. Guitarist John Petrucci has been named as the third player on the G3 tour six times, more than any invited players. In 2009 he was named the No. 2 best metal guitarist by Joel McIver in his book The 100 Greatest Metal Guitarists. He was also named as one of the "Top 10 Fastest Shredders of All Time" by GuitarOne magazine. Jordan Rudess is considered to be one of the greatest keyboard players of all time by many publications like MusicRadar. Former drummer Mike Portnoy has won 26 awards from Modern Drummer magazine and is also the second youngest person (at the age of 37) to be inducted into the Rock Drummer Hall of Fame. His replacement Mike Mangini has also previously set 5 WFD records. John Myung was voted the greatest bassist of all time in a poll conducted by MusicRadar in August through September 2010. The band was inducted into the Long Island Music Hall of Fame in 2010.
The band's highest-selling album is the gold-selling Images and Words (1992), which reached No. 61 on the Billboard 200 chart. Both the 1994 release Awake and their 2002 release Six Degrees of Inner Turbulence also entered the charts at No. 32 and No. 46 respectively and received mostly positive reviews. Metropolis Pt. 2: Scenes from a Memory was ranked number 95 on the October 2006 issue of Guitar World magazine's list of The greatest 100 guitar albums of all time. It is ranked as the 15th Greatest Concept Album (as of March 2003) by Classic Rock Magazine and as the number one all-time progressive album by Rolling Stone (as of July 2012). Six Degrees of Inner Turbulence also led to Dream Theater becoming the initial band reviewed in the music section of Entertainment Weekly during its opening week of release, despite the magazine generally preferring more mainstream music.
The band's eleventh studio album, A Dramatic Turn of Events, was released on September 13, 2011. On November 30, 2011, the album's lead single, "On the Backs of Angels", was nominated for a Grammy Award in the "Best Hard Rock/Metal Performance" category, marking the band's first ever Grammy nomination. Dream Theater's self-titled twelfth studio album was released on September 23, 2013 and earned their second Grammy Award nomination, this time for “Best Metal Performance”, for the album's first single, "The Enemy Inside".
On April 9, 2013, Images and Words won Loudwire's fan voted March Metal Madness for world's best metal album beating albums by Dio, AC/DC, Judas Priest, Megadeth and Metallica. As of 2011, Dream Theater has sold over 12 million records worldwide.