Eleanora Fagan (April 7, 1915 – July 17, 1959), professionally known as Billie Holiday, was an American jazz musician and singer-songwriter with a career spanning nearly thirty years. Nicknamed "Lady Day" by her friend and music partner Lester Young, Holiday had a seminal influence on jazz music and pop singing. Her vocal style, strongly inspired by jazz instrumentalists, pioneered a new way of manipulating phrasing and tempo. Holiday was known for her vocal delivery and improvisation skills, which made up for her limited range and lack of formal music education.