It is just over a hundred years since Billie Holiday was born, one of the great voices of music.

John Szwed has just written his new biography of Holiday, Billie Holiday: the Musician and the Myth. Musically, Szwed is fascinated by the singer's ability to move her voice over the beat of the music.

"To listeners it sometimes sounds as if she's behind the time or off the beat, which she is, but she always knows where she is (in the song)," explains Szwed.

Miles Davis and others also used this technique in their singing, which lends a poignant improvisational style to the music. 

When Holiday's career began the microphone was a relatively new invention for concerts. Before it arrived many singers 'belted' out the song in order for it to reach the back of the venue. Others, like Holiday, preferred the cabaret approach. She managed to translate this technique to the stillness of the microphone.

"When the microphone came in, while she was just beginning, she adapted that table to table feeling," says Szwed.

To listen to the full interview, simply click on the above link.