King Crimson are an English progressive rock band led by Robert Fripp. Their debut album, In the Court of the Crimson King, became one of the foundations of progressive rock. Across changing lineups, the group moved through Mellotron-driven symphonic rock, heavy improvisation, gamelan-like guitar patterns, and experimental rhythm, with works such as 21st Century Schizoid Man, Larks’ Tongues in Aspic, and Discipline.