A Song Is Born (also known as That's Life) is a 1948 Technicolor musical film remake of Howard Hawks' 1941 movie Ball of Fire with Gary Cooper and Barbara Stanwyck, starring Danny Kaye and Virginia Mayo. This version was also directed by Hawks, based on the story "From A to Z" by Billy Wilder and Thomas Monroe, adapted by Harry Tugend (uncredited) and produced by Samuel Goldwyn and released by RKO Radio Pictures.
Filmed in Technicolor, it featured a stellar supporting cast of musical legends, including Tommy Dorsey, Benny Goodman (with Al Hendrickson as cameo), Louis Armstrong, Lionel Hampton, and Benny Carter. Other notable musicians playing themselves in the cast include Charlie Barnet (with Harry Babasin as cameo), Mel Powell, Louis Bellson, The Golden Gate Quartet, Russo and the Samba Kings, The Page Cavanaugh Trio, and Buck and Bubbles. Other actors include Steve Cochran and Hugh Herbert.
(Summary from Wikipedia)