Train of Thought showcased a heavier sound. This decision was inspired by the positive feedback received from their previous heavier songs on stage. 1999's Metropolis Pt. 2: Scenes from a Memory was praised for its display of old-fashioned progressive rock, and was influenced by classic conceptual rock records such as the Beatles' Sgt Pepper's Lonely Hearts Club Band, Pink Floyd's The Wall and The Final Cut, the Who's Tommy, and Genesis's The Lamb Lies Down on Broadway. Dream Theater's music usually borrows elements from other musical styles including symphonic rock, symphonic metal, , soft rock, and classical music. Band members Current members John Petrucci – guitars (1985–present), backing vocals (1989, 1996–present) John Myung – bass (1985–present) James LaBrie – lead vocals (1991–present) Jordan Rudess – keyboards (1999–present) Mike Mangini – drums (2010–present) Former members Mike Portnoy – drums (1985–2010), backing vocals (1989, 1996–2010) Kevin Moore – keyboards (1986–1994) Chris Collins – lead vocals (1986) Charlie Dominici – lead vocals (1987–1989) Derek Sherinian – keyboards (1995–1999, unofficial touring member beginning in October 1994), backing vocals (1997) Timeline Notes Chris Collins was the shortest-serving band member, having only been an official member for a few months; first joining them at the same time as Kevin Moore in the summer of 1986, but parting ways after they did some initial touring following recording their 6-track demo. In the wake of Charlie Dominici's departure from the band in October and November 1989 the band worked with several singers on a temporary basis before fully committing to James LaBrie; they first worked with John Arch, though he was not seriously considering joining the band, then John Hendricks, then Steve Stone (who had a one-off live appearance with the band), then finally Chris Cintron, who they were ready to commit to and officially welcome into the band before James LaBrie's audition arrived. During the 1997-1998 world tour, the band would switch their instruments around for brief "Nightmare Cinema" interludes in the concerts; John Myung played the keyboard, Derek Sherinian played the guitar, John Petrucci played the drums, and Mike Portnoy played the bass. They would often cover Perfect Strangers by Deep Purple during these segments. In 2004, Charlie Dominici and Derek Sherinian joined the band as a one-off on stage during the encore of the March 6th show as guests, to celebrate the 15th anniversary of When Dream and Day Unite. Discography Studio albums When Dream