The screeching violin in "Psycho's" terrifying shower scene. The menacing melody announcing the shark in "Jaws." The lonesome notes signaling potential alien communication in "Close Encounters of the Third Kind." These movies would not pack the same punch without these familiar snippets of music.

Music has always been an integral part of movies, even before "talkies" arrived in the late 1920s. But not many people can hum the soundtracks for "silent" movies because there aren't many recordings of the original scores and many of the scores are missing significant parts. Determined to give this music its place in history, conductor Gillian Anderson has spent two decades restoring and reconstructing scores. She then travels around the world to conduct live orchestras in tandem with screenings, allowing audiences to see and hear these films in their original format.

Anderson has 25 restored scores to her credit, among them Cecil B. De Mille's "The Ten Commandments," Charlie Chaplin's "The Gold Rush" and Fred Niblo's "Ben-Hur," which she will be conducting at the Rehoboth Film Festival on Nov. 13. " 'Ben-Hur' is a real melodrama and it's also a great adventure story," she says. It's a good movie for film festival goers to "cut their teeth on."

Anderson, 56, got her own introduction to silent film scores almost by accident. After earning degrees in biology (an undergraduate interest) and in musicology and library science, she took a job in the music department at the Library of Congress. There, she got intrigued by film music while looking at the score for Carl Theodor Dreyer's 1928 film "The Passion of Joan of Arc." She rented the movie from a public library and made up her mind to synchronize the music with the action.

"I couldn't have started with a worse score," says Anderson. "I had to watch her burn about 100 times before I could figure out where everything went." On her own time, Anderson taught herself the painstaking score restoration process.

"She became our major expert in silent film," says Jon Newson, chief of the music division and Anderson's supervisor. "She was doing pioneering work."

Soon Anderson started conducting the music, with full orchestras and smaller ensembles, at film festivals and special events. And eventually she leapt into the life of an independent artist, her hobby becoming her full-time job. Locally, she has appeared at the National Gallery and Wolf Trap, where each summer the National Symphony Orchestra accompanies a series of silent films (Anderson prefers the term "early" films). Lately Anderson, who lives on Capitol Hill, has been working on several projects in Bologna, Italy, where she founded Cinemusica Viva, an ensemble that specializes in accompanying early films.

The musicologist is one of only a handful of people who restore the scores of old films, a meticulous process that can take up to a year to complete, particularly if many instrumental parts are missing from the score. Anderson gets frustrated with film preservationists who she thinks are interested only in celluloid. "The original work of art was the moving image with a live orchestral accompaniment," she says. "Until both are accomplished, the film is not restored."

When Anderson started work on William Axt and David Mendoza's 1926 score for "Ben-Hur," all that remained of the original work was a piano/conductor score and a violin part. Her job involved filling in orchestration for the rest of the instruments. "I'm not a great film buff," she says. "I don't go see contemporary films. I just watch the same one over and over to synchronize." She saw "Ben-Hur" hundreds of times to determine the right speed of the music as well as cues for when the music starts and stops.

When Anderson conducts, she keeps one eye on the screen and another eye on the orchestra. "It requires a tremendous amount of concentration," she says. "It's not that it's technically difficult. The instrumentalists just never get a rest."

Therefore, when Anderson jumps around Europe, the United States and Canada conducting music for early films, the performances often have an intermission. This makes the experience "more like a theatrical event than the screening of a film," she says. "That aspect appeals to me a lot."

Anderson's career move can be seen as an indication of a rising interest in old movies, says Jeanine Basinger, chairman of the film studies program at Wesleyan University and author of the recent book "Silent Stars." She credits this partly to the cable networks American Movie Classics and Turner Classic Movies. Until they see one, "people think silent films are going to be some humorous exercise in looking at a foolish world of exaggerated gestures," Basinger says. "It's quite the contrary. The performances are honest and true."

She agrees with Anderson that early movies are not complete without the score. "It's like, Venus de Milo looks pretty good without the arms, but it might look even better with the arms," she says. "The score guides you in terms of emotion, attitude and information."

Aside from certain stereotypes of early films, budgets pose another obstacle for Anderson. Her work can be expensive for small organizations to produce. "Doing the 'Ben-Hur' piece is ludicrous," says Barry Becker, director of the two-year-old Rehoboth Film Festival. He paid a music contractor to hire the 11 professional musicians and footed the bill for their rehearsals with Anderson--all for one performance in a 700-seat theater. Still, Becker rationed one-tenth of his $130,000 budget to the production because he says a successful film festival brings out as "many diverse, broad things as possible. 'Ben-Hur' will give us a slightly different audience."

Anderson agrees that the visual element of the movies draws a different crowd to her performances than the typical symphony or contemporary film audience. The experience, she adds, takes people "totally by surprise."

It helps, Basinger says, that the early films and their music are accessible to everyone. "This is not an esoteric art form," she says. "We're not talking about an experience we must be geniuses to understand."

"Ben-Hur" will be screened on Nov. 13 at 7 p.m. at the Rehoboth Beach Convention Center in Delaware. Tickets are $15. For information and tickets, call 302-645-9095 or visit the Web site at Anderson will also give a lecture, "Music and Images," at 10 a.m. on Nov. 14 at the Convention Center.

CAPTION: Gillian Anderson has restored 25 movie scores.