Progressive rock is a subgenre of rock music that emerged in the United Kingdom and the United States during the mid-to-late 1960s. Evolving from psychedelic rock, it sought to elevate rock music through greater artistic ambition and musical sophistication. Traditional song structures gave way to expansive compositions and multi-part suites, often lasting 20 to 40 minutes. The genre is characterized by symphonic influences, intricate arrangements, extended instrumental passages, fantasy-inspired themes, and richly layered orchestration.