Source: Rolling Stone.
McDonald was known as one of the key architects of progressive rock, playing both saxophone and keyboards in King Crimson and co-writing its iconic 1969 debut, In the Court of the Crimson King. The record’s opening track, “21st Century Schizoid Man,” featured McDonald’s wild double-tracked alto-sax solo, which he performed the same year at a famous concert in London’s Hyde Park. He left King Crimson before the year was over, moving on to a duo project with Crimson drummer Michael Giles. He would also appear as a session musician on King Crimson’s 1975 classic, Red.