King Crimson’s 1969 album *In the Court of the Crimson King* is presented as a landmark release that helped establish progressive rock by rejecting conventional pop structures. Its long compositions, prominent brass, extended solos and striking artwork suggested that albums could be more ambitious and experimental than radio-focused three-minute singles.

The article notes that Jethro Tull’s Ian Anderson credits The Nice, Pink Floyd’s *The Piper at the Gates of Dawn* and The Beatles’ *Sgt. Pepper’s Lonely Hearts Club Band* as important early signposts for prog-rock. It argues, however, that King Crimson more fully realised this direction, with former member Greg Lake describing the record as “anti-format” and “something new”.