Many years ago I saw a movie that I believe was filmed in the 40s or 50s. The movie was about a professor teaching classical music in college and is some how asked to sing a more modern song that turns out to be a big hit. The problem is that he does not want anyone to know that it is him that is singing the modern song.

Can you help me out by providing me with the possible name of this movie. I am very interested in seeing it again.

Not sure, but maybe "a song is born" with danny kaye. Not quite the same plot, but similar