 More than 100 recorded versions have been commercially released.Initially, when the song's hopeful sentiment appealed to audiences in the post-World War I era, it was recorded by both singers and instrumentalists, including Morton Downey, Fritz Kreisler, Ted Lewis, and John Steel.Later, as a popular vehicle for improvisation, it was recorded by many jazz musicians, among them Benny Goodman, Duke Ellington, Django Reinhardt, Mel Powell, Jess Stacy, Jack Teagarden and Cuban mambo master Machito.