“As the story came together, Steven looked for a theme—a thread that would connect all of the ideas and elements he had assembled and meld them into a unified whole. He found it in one of his favorite childhood songs: ‘When I heard…‘When You Wish Upon a Star’ from Walt Disney’s Pinocchio (1940), sung by Cliff Edwards, everything kind of fell into place.’ The gentle, wistful tune gave Spielberg the hook he was looking for…and he incorporated it into the script. As soon as he did this, the script found its soul. Steven had taken a story that had begun as cynical thriller about a sinister act and transformed it into a sweet-natured fable about the pursuit of a belief and the fulfillment of a dream.”

Close Encounters of the Third Kind - The Making of Steven Spielberg's Classic Film
Ray Morton