What musician was Joe Glaser involved with that was nicknamed "Lady Day"
Joe Glaser: Joseph G. "Joe" Glaser (December 17, 1896 – June 6, 1969) was an artist manager famous for his involvement in the careers of jazz musicians, including Louis Armstrong and Billie Holiday. Billie Holiday:  Nicknamed "Lady Day" by her friend and music partner Lester Young, Holiday had a seminal influence on jazz music and pop singing.
Billie Holiday