Ian Ernest Gilmore "Gil" Evans (né Green) (May 13, 1912 – March 20, 1988) was a jazz pianist, arranger, composer and bandleader (The Gil Evans Orchestra), active in the United States. He played an important role in the development of cool jazz, modal jazz, free jazz and jazz fusion, and collaborated extensively with Miles Davis Gil Evans was born in Toronto, Canada, as Ian Ernest Gilmore Green and early took the family name Evans from his stepfather.