Between 1944 and 1948, Miles Davis played trumpet in Charlie Parker's quintet and realized he could not match the blistering speed or piercing high notes of Parker and Dizzy Gillespie. This deep dive examines how that artistic crisis led him out of bebop and into Gil Evans's basement apartment on 55th Street, where a group of musicians fatigued by velocity studied the Claude Thornhill Orchestra's vibrato-free, choir-like sound and designed a nine-piece band to capture it.

The episode breaks down the nonet's unusual architecture, with trumpet and alto on melody, trombone and French horn on harmony, and baritone sax and tuba on counterpoint, and the meticulous charts written by Evans, Gerry Mulligan, and John Lewis. It then follows the mixed September 1948 debut at the Royal Roost, three fragmented sessions between January 1949 and March 1950 ...