Liquid Tension Experiment is an American instrumental progressive metal supergroup formed in 1997 by drummer Mike Portnoy. Known for their technical musicianship and energetic compositions, the group originally released two influential albums in 1998 and 1999. After a period of inactivity due to members' commitments to other projects, they reunited several times, producing live albums and offshoots under the name Liquid Trio Experiment. In 2021, the band returned with their third studio album, marking a full reunion of the original lineup. Their work is celebrated for its virtuosity and innovation within the progressive metal genre.