Oh, You Beautiful Doll (1949)

In the early 1900s, song plugger Larry Kelly chances to meet Alfred Breitenbach, poor opera composer...and his lovely daughter Doris, who falls for Larry. To improve their acquaintance, Doris conspires with Larry to turn her father's opera melodies into popular songs. Alfred, reluctant but needing cash, adopts the pen name Fred Fisher. Affluence results, but when Alfred realizes his opera is vanishing bit by bit, he wants to bring the career of "Fred Fisher" to a halt...