William P. Gottlieb, Down Beat, v. 13, no. 20 (Sept. 23, 1946), (Copyright)
Duke Ellington born:

April 29, 1899
Edward Kennedy Ellington was born in Washington, D.C., the son of James Edward and Daisy Ellington. His father was a butler, and his mother held various jobs as a domestic and government worker. He was given the name Duke in 1913 by a high school friend named Edgar Mcentree, who was impressed by his clothes and smooth manner.
Source: Beyond Category: The Life and Genius of Duke Ellington By John Edward Hasse, 1/1/1900

Library of Congress, Prints & Photographs Division, Carl Van Vechten Collection
Ella Fitzgerald born:

April 25, 1918

Source: Library of Congress, 4/25/2007

Billie Holiday is born:

April 7, 1915
Jazz singer Billie Holiday was born on April 7, 1915, in Baltimore, Maryland.
Source: Library of Congress, 4/7/2007

  Billie Holiday is discovered:

One night in 1933, Monette Moore was supposed to perform at the club bearing her name on 133rd Street in Harlem. Moore had received a part in a Broadway show, and asked Holiday, then , to replace her. Holiday opened with a song called "Wouldja for a Big Red Apple?", improvising as she moved from table to table. In the audience was a young music producer named John Hammond, who brought Bennie Goodman and Joe Glaser (Louie Armstrong's manager) uptown to hear her.
Source: Billie Holiday, Kliment, 1/1/1900