The progressive rock pioneers’ jazziest album gets jazzier! King Crimson formed, played to an estimated crowd of 500,000 at Hyde Park, birthed progressive rock on In The Court of the Crimson King, and disbanded by the end of 1969. Guitarist Robert Fripp took the reins as the group entered an interregnum. For the next two years, Crimson survived on session players and members who left almost as soon as they joined, lacking a definitive lineup to sustain the touring circuit.