Interestingly, the fact that the music tends to fade along with memory of the film has less to do with the quality of the music — some of the best music composed in the 20th century was film music — than with the fact that the music is only half the equation. Film music is a true melding of arts, each dependent upon the other.

In an innovative move, assistant conductor Joan Landry programmed a mix of music, film, and film music Friday night.

The first half presented suites from two of the greatest films of the 20th century: Warner Brothers' 1938 "Robin Hood," starring Errol Flynn, Olivia de Havilland, Basil Rathbone and Claude Rains, with an Oscar-winning musical score by Austrian-American Erich Korngold; and the 1954 film "On the Waterfront," directed by Elia Kazan, starring Marlon Brando and Eva Marie Saint, with an Oscar-nominated musical score by Leonard Bernstein.

Both suites offered exciting music, Korngold's more late Romantic and sectional, Bernstein's more rhythmic, jazzy, and musically coherent. In fact, Bernstein essentially re-composed the music into a symphonic suite in order to "save" the music from being lost to the film and dubbing room floor.

Both also featured colorful scores that showcased musicians: Todd Yukumoto (saxophone), Toshie Ueda (piano), Mark Schubert (trumpet), Erica Peel (flute), the entire percussion section (Stuart Chafetz, Matthew McClung, Eric Shin, Riely Francis, and Ira Wong), and especially Jonathan Parrish (French horn), who delivered outstanding solos both on stage and off.

The second half of the concert presented "Kensei Araki Mataemon," (Araki Mataemon, Master Swordsman), a 1934 silent film starring Seshu Hayakawa, on a large screen above the orchestra.

Originally, silent films had a single, visual focus. Friday's showing was a multi-media "silent-film-plus": plus a narrator, plus English subtitles on a separate screen, and plus symphonic music. The challenge for the audience was to know where to focus their attention.

The most compelling element proved to be Midori Sawato, a wonderfully expressive "benshi," or Japanese silent film narrator. Working from what looked to be a handwritten script, Sawato retold a detailed story, speaking for characters and adding vocal effects in effect weaving a spell so complete that the film seemed conjured from her words.

Disappointingly, the English subtitles translated none of Sawato's vivid tale, only the terse phrases shown in the film, leaving non-Japanese speakers on imagination's sidelines.

The accompanying music, which Landry spent months compiling, presented a mirror image of the concert's first half. The first half was excerpts of film music compiled to create a concert work; the second half was excerpts of symphonic music deconstructed to accompany a film.

The accepted masterworks — Debussy's "Nocturnes," Shosta-kovich's "Symphony No. 10," Dvorak's "Symphony No. 7," and reprises from Korngold's "Robin Hood Suite" — were no more adept at garnering attention than standard film music: Despite explanations in the program and before the concert, a fair number in the audience did not notice that the works listed had been played during the film, and they were surprised the concert was over when the film ended.

In fact, the music was most noticeable when the course of the music did not match that of the film, creating almost surreal incongruities, and it was least noticeable when the two matched well, its coherence dissolving into that of the film. The Honolulu Symphony played well, but did anyone notice?

Therein lies the conundrum: effective film music cannot be cobbled together, but all that work of composing to fit the film results in music that has no life of its own. The focus remains firmly with the film, the coherence lies in the drama, and even the music's renown is tied to the film.