In the final scene of Modern Times, Charlie and the gamine set off down the road to a new life.
When they get up off the grass verge to go, he pauses and points to the corners of his mouth, indicating that she should smile.
"Smile" has become a popular standard since its original use in Charlie Chaplin's film and has been recorded by numerous artists.
"Smile" is a song based on the theme song used in the soundtrack for Charlie Chaplin's 1936 film Modern Times.