I just learned in Ira Glass’ interview in the Times that this scene from my favorite film A Thousand Clowns is not only incredibly powerful in the context of the story, it’s also the birth of the falling-in-love montage. It’s hard to imagine a world without a man and a woman going to the movies and walking along a pier and maybe sharing some cotton candy while a pop song plays, but apparently, this was the start of that. Editor Ralph Rosenblum.
The context, by the way: Jason Robards’ character, Murray, has driven one two Child Protective Services personnel out of his house with blithe, jokey behavior, despite the incredible stakes of his meeting with them - they’re going to take away his nephew. Still, he pushes the blitheness further by singing a duet with the nephew, trying to charm the CPS woman (Barbara Harris) who remains.
It works - she falls in love with him. Because he’s so immensely charming. To her and to us. But it’s dramatic irony. The audience knows that his charm is not his greatest strength, but his greatest weakness. Because what he needs to do is change, to grow up, so he can keep his nephew and give him a chance in the world. So it’s really a montage where we fall in love with him, too… but know the pain that will come from it.