Lester Young
Saxophonist
Influential jazz saxophonist called "The President" by Billie Holliday and who created the West Coast cool style.
He was rejected from military service due to a diagnosed addiction to drugs and alcohol, as well as his "nomadism."
He has had influence far outside of jazz; his speaking and dressing style and every mannerism was imitated. He might have even inspired the term "cool" to mean fashionable.
He was born in Woodville, Mississippi and grew up near New Orleans, which influenced his style.
Legendary jazzmen like Charlie Parker, Stan Getz, and John Coltrane all cited Young as a major influence on their work.