Porcupine Tree is an English rock band formed in 1987 in Hemel Hempstead, Hertfordshire, England. Originally Steven Wilson's solo project, by late 1993, Wilson brought on frequent collaborators Richard Barbieri as keyboardist, Colin Edwin as bassist, and Chris Maitland as drummer to form the first permanent lineup. With Wilson as lead vocalist and guitarist, this remained the lineup until February 2002. Porcupine Tree's early sound evoked various styles of psychedelic rock, space rock, and experimental rock, later moving towards a more progressive/space rock direction comparable to that of Pink Floyd, shifting to more mainstream alternative rock sound in the 1990s, and a more progressive metal direction in the early 2000s. The band became publicly inactive in 2009. However, Wilson, Barbieri and Harrison continued to intermittently work on material in secrecy over the course of the following decade, leading to the release of their album Closure/Continuation in 2022. ...more on Wikipedia