Birth of the Cool is a compilation album by American jazz musician Miles Davis, originally released in 1957 on Capitol Records. It compiles twelve tracks recorded by Davis's nonet for the label over the course of three sessions during 1949 and 1950. Featuring unusual instrumentation and several notable musicians, the music consisted of innovative arrangements influenced by classical music techniques such as polyphony, and marked a major development in post-bebop jazz. As the title implies, these recordings are considered seminal in the history of cool jazz. Most of them were originally released in the 10-inch 78-rpm format and are all approximately three minutes long.