"Lady Day" Billie Holiday (born Eleanora Fagan [April 7, 1915 -- July 17, 1959) was an American jazz singer and songwriter. Nicknamed "Lady Day" by her friend and musical partner Lester Young, Holiday had a seminal influence on jazz and pop singing. Her vocal style, strongly inspired by jazz instrumentalists, pioneered a new way of manipulating phrasing and tempo. The Chicago Blues Museum is a registered trade mark / (501c3)