Multi-instrumentalist and songwriter Ian McDonald, best known for his co-founding roles in both King Crimson and Foreigner, died Wednesday at the age of 75. 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. Guardian describes him as "a galvanising force in the group’s potent mix". McDonald also co-founded rock outfit Foreigner with guitarist Mick Jones.

Guitarist Anthony Garone wrote a book 'Failure to Fracture' chronicling his 22-year-long journey of learning how to play King Crimson’s 11-minute instrumental 'Fracture', Guitar World reports. Robert Fripp once described his 1974 masterpiece as “impossible to play”, especially because of the section roughly three minutes in where the guitarist begins a nonstop barrage of notes called a “moto perpetuo” – an Italian term for “perpetual motion”. Over the years, Garone published blog posts and videos about his efforts, and kept working at it until he had a breakthrough after enrolling in a week-long guitar instruction course led by Fripp in rural Mexico in 2015. Last year Garone released a video of him playing the song (watch it below). 'Failure to Fracture' is released May 18.