Mike Portnoy has formed several groups.
Mike Portnoy . He is a founding member of Liquid Tension Experiment , an instrumental progressive rock band featuring fellow Dream Theater members John Petrucci and Jordan Rudess along with bassist Tony Levin . He is also a founding member of Transatlantic , a progressive rock `` super-group '' featuring former Spock 's Beard keyboardist/vocalist Neal Morse , Flower Kings guitarist Roine Stolt and Marillion bassist Pete Trewavas . Since leaving Dream Theater , Portnoy has formed several new bands .