Both the book, The Lady Sings The Blues, and the play, Lady Day At Emerson Bar and Grill, tell the story of Billie Holiday (1915-1959), an American jazz singer and song-writer.

The difference between the two is that the book is an autobiography of Holiday's life, while the play centers on an actress (acting as Holiday) singing tunes which tell of the most pertinent experiences of Holiday's life.

You can read a biography of Billie Holiday at the PBS (Public Broadcasting Service) website here.

As for Holiday's autobiography, some contend that the book consists of factual inaccuracies. However, many critics admit that the book highlights the authenticity of Holiday's unique voice as she tells the story of her colorful life. From the pages of The Lady Sings The Blues, Holiday speaks poignantly about abusive relationships, heroin addiction, the Jim Crow laws and racism, incarceration, alcoholism, and teenage prostitution. Holiday's autobiography was released simultaneously with her album of the same name, in 1956. The 1972 film of Holiday, starring Diana Ross as Holiday, and Billy Dee Williams as her husband, Louis McKay, was loosely based on Holiday's autobiography.

You can read a review of Billie Holiday's book here.

As for the play, Lady Day at Emerson Bar and Grill, the most famous Broadway performance of Billie Holiday's story is the one in which the inimitable Audra McDonald stars as Holiday. McDonald's performance won her critical acclaim and many awards. In between famous tunes like What a Little Moonlight Can Do and T'aint Nobody's Business If I Do, McDonald, as Holiday, recounts tales of love lost and of supreme heartache.

You can see the Broadway website describing Audra McDonald's performance here. The last Broadway performance of Lady Day at Emerson Bar and Grill was in 2014.

A critique of the play by the New York Times can be read here.