Her delivery made Billie Holiday's performances recognizable throughout her career. Her improvisation compensated for lack of musical education. Her voice lacked range and was thin. Years of drugs altered its texture and gave it a fragility. Her voice also included a raspy sound. Holiday said that she always wanted her voice to sound like an instrument and some of her influences were Louis Armstrong and singer Bessie Smith. Her last major recording, a 1958 album entitled Lady in Satin, features the backing of a 40-piece orchestra conducted and arranged by Ray Ellis, who said of the album in 1997:
I would say that the most emotional moment was her listening to the playback of "I'm a Fool to Want You." There were tears in her eyes ... After we finished the album I went into the control room and listened to all the takes. I must admit I was unhappy with her performance, but I was just listening musically instead of emotionally. It wasn't until I heard the final mix a few weeks later that I realized how great her performance really was.
Frank Sinatra was influenced by her performances on 52nd Street as a young man. He told Ebony in 1958 about her impact:
With few exceptions, every major pop singer in the US during her generation has been touched in some way by her genius. It is Billie Holiday who was, and still remains, the greatest single musical influence on me. Lady Day is unquestionably the most important influence on American popular singing in the last twenty years.