1670 - King Crimson In the Court of the Crimson King 1969

One of the most influential progressive rock albums of all time, King Crimson's debut eschewed the bluesy bluster of late-Sixties British rock for a Mellotron-drenched mixture of jazz and classical influences, dragging psychedelia to a darker place than it had ever been before. With guitarist Robert Fripp and multi-instrumentalist Ian McDonald piling on layers of majestic sound, and bassist Greg Lake intoning evocative and foreboding lyrics, tracks like the stately closer "The Court of the Crimson King" set the tone and template for the coming prog revolution.

954 - King Crimson 21st Century Schizoid Man 1969

King Crimson’s music drew on a wide range of influences provided by all five group members, including Jimi Hendrix, romantic- and modernist-era classical music, folk, jazz, military music (partially inspired by McDonald’s stint as an army musician), ambient improvisation, Victoriana and British pop.
Their debut album "In the Court of Crimson King" starts off with the fiery "21st Century Schizoid Man," a mix of scathing proto-metal and fiery jazz.