MULMUZZLER is an outside activity of DREAM THEATER frontman Kevin James LaBrie. The debut August 1999 set 'Keep It To Yourself', released through Magna Carta Records, featured LaBrie alongside keyboard player Matt Guillory, known for his work with DALI'S DILEMMA, drummer Mike Mangini is a veteran of both EXTREME and ANNIHILATOR, guitarist Mike Keneally with Bryan Beller on bass. Supporting musicians included Trent Gardner, on keyboards, trombone and programming on 'Beelzebubba' and 'As A Man Thinks', Greg Critchley with drums on 'As A Man Thinks', Mark Shannon, bass and fretless bass on 'As A Man Thinks',  Dave Townsend with guitar on 'Shores Of Avalon', plus Michael Stewart with trumpet and alto sax on 'Beelzebubba'. The sessions were recorded at M.I.Studios in Los Angeles, California and Town Studios in Toronto, Canada. The tracks were mixed by Terry Brown, noted for his work with RUSH.

The band line-up for the second album, September 2001's 'James LaBrie's Mullmuzzler 2', remained stable with the addition of guitarist Mike Borkosky. MAGELLAN's Trent Gardner also featured.