 As a student at Cass Technical High School she played string bass in the school orchestra, studied piano and voice on weekends, and sang in her church's choir.An elder brother introduced her to jazz, Cook chose voice as her instrument of choice, and she became a disciple of jazz icon Eddie Jefferson, founder of a singing technique called "vocalese" where a singer sings lyrics to a famous instrumental solo.During this time she and close friend Regina Carter formed dreams of becoming jazz musicians; Cook as a singer, and Carter as a violinist.