"Rock In Opposition" (RIO) is a musical movement that emerged in the late 1970s, primarily in Europe. It was founded by a group of progressive rock bands who sought to create music that defied commercial norms and embraced artistic freedom. The movement aimed to promote avant-garde and experimental music, often characterized by complex structures and unconventional sounds. The first official RIO concert took place in 1978 in London, featuring bands like Henry Cow, Stormy Six, and Univers Zero. RIO served as a platform for musicians to collaborate and share ideas, fostering a community that valued innovation over mainstream appeal.