Shirley Horn was born and raised in Washington, D.C.. Encouraged by her grandmother, an amateur organist, Horn began piano lessons at the age of four. Aged 12, she studied piano and composition at Howard University, later graduating from there in classical music. Horn was offered a place at the Juilliard School, but her family could not afford to send her there. Horn formed her first jazz piano trio when she was 20. Horn's early piano influences were Erroll Garner, Oscar Peterson and Ahmad Jamal, and moving away from her classical background, Horn later said that "Oscar Peterson became my Rachmaninov, and Ahmad Jamal became my Debussy." She then became enamored with the famous U Street jazz area of Washington (largely destroyed in the 1968 riots), sneaking into jazz clubs before she was of legal age.