If you've never heard a John Williams score, chances are you've limited your movie-viewing experiences to German expressionist films. Hey, if that's what you're into, that's cool, but should you decide to branch out one day, sooner or later you'll hear a John Williams score.
Williams has composed the music for roughly 80 films throughout his six-decade career. He's won five Oscars, 17 Grammys, three Golden Globes, two Emmys and five BAFTA Awards. (Source) In other words, if you get a Trivia Pursuit question about a movie composer, just guess John Williams and there's a 75 percent chance you'll be right.
Of his 80+ scores, many of them have been for Steven Spielberg films, including three of his Oscar winners. Williams first composed for Spielberg in 1974 with The Sugarland Express. Since then, the two have collaborated on every feature film Spielberg has directed, with only two exceptions, The Color Purple and Bridge of Spies. Many of these scores have entered our cultural consciousness. Seriously, is there anyone who wouldn't recognize the theme from Jaws or Jurassic Park or E.T.? Maybe, but good luck finding them.
Close Encounters is the third collaboration between Spielberg and Williams. Speaking on the use of music in Spielberg's films, Williams said,
I think that there's something about Steven's movies that require almost that the music be a partner in the narrative. And that it either follows the story, or leads the story, or describes the story, probably all three functions as we go through the film. (Source)
When Lacombe teaches the E.T.-looking alien the hand signs for the five-note phrase, the score is all uplifting strings and winds, and the vocals are light and airy—the direct opposite of the haunting vocals we heard in "Barry's Kidnapping," and the atonal, discordant scoring early in the film.
This tonal shift is to musically clue us into the film's happy ending. The aliens aren't a threat as the characters initially feared (and the earlier tracks suggested). They are searching for the same thing humans crave, companionship. And they've found it. As such, the final music cue is one of triumph at the end of a successful mission for both humanity and its new extraterrestrial neighbors. Williams even incorporates "When You Wish Upon a Star" into those final moments of the score. How more hopeful can you get?