Most people consider film to be purely visual. Yet a movie's music, or score, plays a key role in conveying the work’s message.

Joseph Rivers, who teaches film studies and music at the University of Tulsa in Oklahoma, says the musical theme for director Stephen Spielberg's "War Horse," the epic that opens in rural England,  is a good example of the way music can enhance the audience experience of a place.  

“With "War Horse," this is done through sustained harmonies, broad sweeping orchestrations, sweeping melodic lines, or even with folk-like melodies imposed on the harmonies."

Five-time Oscar winner John Williams composed the music for "War Horse," one of the five nominees for best score.

Williams garnered another bestsScore nomination for "The Adventures of Tintin," an animated blockbuster based on a Belgian comics series.

For Daniel Carlin, chairman of the film scoring department at the Berklee College of Music, nail biting excitement is the key to Tintin’s success.

“John is a master at the use of space," Carlin says. "He'll leave a bit of a hole for the sound of gunshot or a hit to a face or a crash, and then he’ll come in with a statement rather than, as many composers do, try to compete with the sound. I personally felt that "Tintin" was a more successful score than "War Horse."

For Rivers, the artful way that Iglesias conveyed Cold War suspense and intrigue is what earned him his Oscar nomination. “I think he does an excellent job of setting the atmosphere.”

Sometimes, highbrow musical ideas can be used to good effect by Hollywood, as in the case of "Hugo."

Film composer Wendy Blackstone has scored for eight Oscar nominees over the years. She hears echoes of minimalism in Howard Shore’s score for “Hugo,” an adventure drama about a boy living in a Paris train station.

“It has repetitive clauses in it that give a lulling kind of center to it which we can attribute to Terry Riley, Philip Glass and these forerunners of that kind of music," Blackstone says.

Whatever the composer's style, it must always serve the director’s vision.

“There are moments when the music can shine," Blackstone says. "But then there are moments when it should be out of the way and felt not heard."

Many critics believe French composer Ludovic Bource is the odds-on favorite to win best score for “The Artist.” It’s a mostly silent film, set during the late 1920s and early '30s, when silent films were giving way to the talkies.

Bource's score runs the emotional gamut.

For Berklee's Daniel Carlin, "The Artist" is a film composer's dream.

“I mean there are plenty of people that would have done this project for free if they'd been given the opportunity. You are not worried about dialogue or train wrecks or gunshots or door slams or car squeals. None of that stuff," Carlin says. "But it also makes one fully exposed. It doesn’t leave much room for error or padding. And I felt that this composer did a very diligent job of not taking shortcuts, of giving every scene its due, of somehow staying within that period without making it sound like we are listening to old music.”

All of the nominees will have to wait until Feb. 26, to learn who will score the “Best Score” Oscar.