Today's episode is all about music history. First, musicologists Kerry O'Brien and William Robin tell NPR's Noah Caldwell about their new book, On Minimalism, and how the genre was born out of 1960s counterculture and went on to influence artists like The Who and Alice Coltrane. Then, Lesa Cline-Ransome and James E. Ransome tell NPR's Samantha Balaban about their new picture book, The Story of the Saxophone, which chronicles the instrument's journey to becoming one of jazz's most important players.