On this day (August 14) in 1947, trumpeter Miles Davis recorded his first album as a leader. He was all of 21 years old, but by then the future jazz legend had already attended (and dropped out of) The Juilliard School and played in bands led by Charlie Parker and Dizzy Gillespie. On his first recording under his name, he’s backed by musicians who would each go on to radically change the shape of jazz: Parker on saxophone, John Lewis on piano, Max Roach on drums and Nelson Boyd on bass. (The group’s name — The Miles Davis All-Stars — may just be the understatement of the century.) Our Song of the Day is “Sippin at Bell’s,” an unconventional 12-bar blues written by Miles Davis as a tribute to one of his favorite bars in Harlem. It’s the sound of jazz history in the making.