Transatlantic is a multinational progressive rock supergroup consisting of Neal Morse (ex–Spock's Beard), Roine Stolt (Kaipa, the Flower Kings), Pete Trewavas (Marillion, Edison's Children) and Mike Portnoy (ex–Dream Theater). They formed in 1999 as a side project to their full-time bands, but disbanded in 2002. They then reunited in 2009.

Despite not being an official member and only appearing on one studio album, Daniel Gildenlöw (Pain of Salvation) has often joined the band during live shows. However, due to illness, Ted Leonard (Spock's Beard, Enchant, Thought Chamber) stood in for him during the 2014 tour. Leonard also joined the band during the 2022 tour.

Source: Wikipedia (https://en.wikipedia.org/wiki/Transatlantic_(band))