For 60 years, John Coltrane’s ‘Ascension’ has stood as a monument—a nearly 40-minute declaration of artistic independence that signaled his embrace of the growing jazz avant-garde. Sixty-one years ago this week, Coltrane assembled 10 adventurous young musicians at Rudy Van Gelder’s studio, including Pharoah Sanders, Archie Shepp, Marion Brown, and Freddie Hubbard, alongside members of his own quartet. The results have divided listeners for six decades, but for Coltrane there was no turning back.