Film Composer John Williams has a talent for creating fantastic themes that capture the essence of a film. We only have to hear the first rapid beats of "da-da-da-da! Daaa dum da daaa!" and the image of a handsome Indiana Jones with his iconic hat and whip comes to mind. The same as Williams' theme for "Jaws" (1975) and the Star Wars saga. And the five tones used in "Close Encounters of the Third Kind" (1977), is no exception.

The film was Steven Spielberg's first foray after his critically-acclaimed and blockbuster debut of "Jaws" (1975). Although the then 31-year old director was a star in the studios eye, they did not have a lot of confidence in the project at first. So, Spielberg was attentive to every detail of the story, production and of course, the music to make sure he produced the best film he possibly could, to prove the studios wrong. Again.

For the music, he chose to use Academy-Award winning composer and friend John Williams. Thanks to Spielberg's "Jaws" (1975), Williams received his first Oscar for the film's score and Spielberg knew that he could deliver.

When he consulted with Williams on the music, Spielberg had an idea for what he wanted the theme to stand for. He once remarked in an interview, "No rhythm. Just five notes." In another interview Spielberg said, "I just felt like 5 notes would be much more like a HELLO. And 7 notes would suddenly sound like a melody. I didn’t want a melody. I wanted a greeting."

Williams experimented with 350 out of approximately 134,000 five-note combinations that are available on the 12-tone chromatic scale. One of the fascinating facts about the five final notes is that Williams composed them to make sure that two of the notes are the same, like the double "l"'s in "Hello." For musicians and music theorists, the five tones belong to the Ab Major Pentatonic Scale, which for the rest of us, means "happy, neutral" tones to sound pleasant and welcoming to the aliens.

The hand motions that accompany the notes in the film's intergalactic climax, follow the "Kodaly Method." Originally, the hand motions serve as a visual aid during singing and voice exercises. In film uses the hand motions as a visual communication to the aliens.

Perhaps Spielberg did not know it, but once "Close Encounters of the Third Kind" (1977) made a huge impact on how sci-fi could be taken seriously as a film genre. Before "Close Encounters", any film that were on the subject of aliens, were left to cult classic B-films, but "Close Encounters" was a game changer for the film genre. "Close Encounters" was nominated for eight Academy Awards including for "Original Music Score". In its legacy, "Close Encounters" is considered one of the first films to explore the serious issue of what it would mean for aliens to make contact with Earth. Most importantly, what it would be like if the meeting was amiable and friendly one.