Kevin Moore was born on May 26, 1967, in King's Park, New York. He started learning the piano at age six and wrote his first song by age twelve, when he asked John Petrucci to join in his first band. He enrolled at SUNY Fredonia, studying classical music. That Christmas break Petrucci approached Moore to join his band, Majesty. Moore played with the band during break and then joined full time after the first year of school, adding keyboard parts to songs already written by the band.
During his tenure with Majesty (later Dream Theater), Moore wrote lyrics to some of the band's most complex and deep songs, such as "Only A Matter of Time," "Wait for Sleep," and the band's eventual breakthrough hit, "Pull Me Under." However, Moore tired of the creative boundaries that were set by being in a band. After recording Awake with the band in 1994, Moore announced he would be leaving Dream Theater to focus on more independent projects. The final song on Awake, "Space-Dye Vest" was written solely by Moore, and is one of only two Dream Theater songs that has never been performed live by the band.
Moore moved to New Mexico and focused on composing solo works. During this time he wrote many demos that were compiled on his 1999 solo album, This is a Recording. He has released three albums under the name Chroma Key, the most recent being 2004's Graveyard Mountain Home. His other project is OSI, short for the short lived Office of Strategic Influence, along with Fates Warning guitarist Jim Matheos. This project also featured Mike Portnoy as a guest drummer on the first two albums. OSI has released three albums, the most recent being 2009's Blood.
Moore has not collaborated with Dream Theater since leaving in 1994, stating he would rather move forward than look back. This has caused some tension with fans and members of the band. In 2007 he performed his first live solo show in over a decade in Turkey, where he currently resides.