Rhythm on the River

Rhythm on the River is a 1940 musical comedy film starring Bing Crosby and Mary Martin as ghostwriters whose songs are credited to a composer played by Basil Rathbone. Crosby and Martin sang Only Forever, for which James V. Monaco music and Johnny Burke lyrics were nominated for the Academy Award for Best Original Song.

After his lyric writer dies, Oliver finds a replacement in Cherry Lane Mary Martin. She is reluctant about being a ghost writer, but accepts his offer. He is satisfied with her first lyric. She becomes ambitious to write better lines, but is not able to concentrate at home, and it is suggested she move to a small and quiet place. Meanwhile, Bob and Cherry meet several times, without knowing they are working for the same employer. She does not think highly of him.To work in a perfect environment, Cherry travels to Tarrytown and stays at Nobodys Inn. Bob decides to give the inn a visit at the same time, and they are shocked to run into each other yet again. They soon become acquainted and actually start liking each other. They even compose their own song together. However, because they are not allowed to tell who they are working for, they do not find out they are colleagues. She becomes mad at him when he plays the song she wrote the lines for and states he wrote it himself. ........

Source: Wikipedia