There was a time, within living memory, when the most famous piece of original orchestral film music was “Tara’s Theme,” Max Steiner’s sweeping evocation of the O’Hara Plantation in the 1939 epic “Gone With the Wind.” But “Tara’s Theme” was supplanted in an instant when “Star Wars: Episode IV – A New Hope” appeared in 1977.

Within months, just about everyone knew the film’s bold, military opening theme, and it wasn’t long before some of the gentler sub-themes were just as widely known. And the score’s composer, John Williams, was suddenly a household name.

Actually, connoisseurs of film music already knew him well: Williams had been composing film music since the late 1950s, and his resume included scores for “How to Steal a Million” (1966), “The Valley of the Dolls” (1967), “Goodbye Mr. Chips” (1969), “The Paper Chase” (1973) and “The Towering Inferno” (1974). His most famous score, by then, was for “Jaws,” music that won a place in the popular consciousness on the strength of its tense, pulsing theme, heard whenever the shark was about to attack.

Williams, in fact, was something of an anachronism. By the 1970s, most people attended movies with barely a thought for the music that underscored what they were seeing, and Hollywood was edging toward a new model in which film scores were actually just compilations of pop songs, some new, some old.

But in “Star Wars,” Williams beat the historical tide by turning back the clock and taking audiences with him to Steiner’s day – and deliberately so, since George Lucas modeled the film on the sci-fi serials of the 1930s and 1940s. Stirring, ear-catching music was a crucial element of a production that was meant to be simultaneously high tech and retro.

But Williams provided more than that. By using the techniques of the late 19th- and early 20th-century composers of opera and symphonic music, and by alluding to specific scores in the standard canon, Williams showed the extraordinary degree to which music is a language, and that its elements – melodic shape, harmony, orchestral color and more – can be combined in ways that create a huge vocabulary. That vocabulary is primarily emotional, but it is also descriptive enough to evoke action, place and, most importantly, character.

To do that, Williams took a page from Richard Wagner’s playbook and used leitmotifs, or short, instantly recognizable themes, to portray the film’s central characters as well as non-corporeal concepts like the Force. The point of a leitmotif, of course, is to capture an essential quality beyond what we learn from a character’s actions and words, and it can be varied and rescored (playfully, tragically), or combined with other characters’ themes, as the circumstances demand. Once you know the leitmotifs, you can hear the score without watching the film, and know what’s going on.

Luke Skywalker actually has two themes – the central brassy, heroic figure of the “Star Wars” opening music, which shares its arching shape with Alexander Courage’s “Star Trek” theme (itself a distillation of passages from Samuel Barber’s “Second Essay for Orchestra”), and a theme that combines nobility and a touch of lugubriousness, one that is also associated at times with Obi-Wan Kenobi and the Force. They tell us about the gallant Jedi he will become before we even know what that is.

And then there’s Darth Vader and his Imperial cohort. In the first film, Vader is portrayed with merely a rising two-chord figure for brass and winds. The pounding Imperial March (with its roots in Dmitri Shostakovich’s music) that has become so closely associated with him did not enter the saga until the second film, “The Empire Strikes Back.”

Beyond the character themes, Williams’ music magnifies what our eyes tell us. When we first see the Dunes Sea of Tatooine, for example, a repeating two-note wind figure under a sustained, high string tone – a simplification of language from Claude Debussy’s “La Mer” – captures the scene’s desolation more thoroughly than Lucas’ panoramic shot. Does it matter whether you know the Debussy work? Not at all. The “sea” imagery comes through in any case; Debussy used those harmonies and orchestral colors for a reason.

The same with the scene in which Luke finds the smoldering ruins of his home, and realizes the Imperial troops have murdered his aunt and uncle. Williams uses the first four notes of the Dies Irae, the Gregorian chant for the dead, a theme many composers have quoted. If you recognize it, it’s a bonus, but if you don’t, the Dies Irae melody has an inherently dark quality that suggests pathos and tragedy. (Williams returns to it at appropriate moments in the prequels.)

And on and on: Prokofiev’s scoring styles are among those drawn upon in battle scenes, hints of Holst’s “The Planets” find several uses. It’s hard not to think of the wedding music from Felix Mendelssohn’s “A Midsummer Night’s Dream,” tempered with Sir Edward Elgar’s “Pomp and Circumstance” marches, in the medal-bestowing scene that closes the first film.

In the prequels, where Williams is generally more freewheelingly modernist (particularly in his percussion writing), choral writing with links to Orff’s “Carmina Burana” underpin scenes involving Darth Maul and the newly villainous Anakin. Instead of remaining locked in to the themes he created for the first three films, he created new ones for the younger versions of Obi-Wan and Darth – to say nothing of those for a full slate of new characters. And he can be expected to expand his palette, and his ingenuity for character-defining and action-magnifying themes, in “The Force Awakens.”

Scene for scene, Williams’ “Star Wars” music has so far been the perfect accompaniment for the images we see on the screen, and it makes an ideal case for the artistry involved in film scoring, a part of movie-making that too many viewers take for granted.

Williams occasionally makes that case more directly, too. I once saw him conduct a concert of film music (his own and Bernard Herrmann’s) in which he presented a chase scene from “Indiana Jones and the Last Crusade” without its score. It was an inherently exciting scene that lasted only four minutes, but without the music, it seemed needlessly long. When he showed the scene again, accompanied by his vital, dramatic music, the chase flew by in no time, and you were on the edge of your seat for all of it.

The “Star Wars” films without music – or with any other music – would be unimaginable.

Allan Kozinn is a former music critic and culture writer for The New York Times who lives in Portland. He can be contacted at:

allankozinn@gmail.com

Twitter: kozinn