Liquid Tension Experiment (LTE) is an American instrumental progressive metal supergroup founded by Mike Portnoy, in 1997. The band initially released two albums, between 1998 and 1999. An extension of their second regular album, with the absence of John Petrucci was released in 2007 under the name "Liquid Trio Experiment".

Progressive metal is a broad fusion music genre melding heavy metal and progressive rock, combining the loud "aggression" and amplified guitar-driven sound of the former with the more experimental, cerebral or quasi-classical compositions of the latter.