Peter Sinfield, Poetic Lyricist for Prog Rock’s King Crimson, Dies at 80 By November 22, 2024Art His swirls of imagery helped define progressive rock in the 1970s. He later turned his focus to pop acts like Celine Dion. His swirls of imagery helped define progressive rock in the 1970s. He later turned his focus to pop acts like Celine Dion.