Was there ever a more ardent proselytizer for classical music than Amadeus? That the Philadelphia Orchestra spent nearly three hours Thursday night performing under the silver screen as the movie played is probably the only answer you need.

The film, made nearly 35 years ago, has managed to keep its grip on several distinct subspecies of cultural consumer: film buffs, the armchair musicologists who enjoy not enjoying its artful handling of the historical facts, and the stray classical geek who sits in the theater too overjoyed for words to learn that there are others who hear in this music what he does.

It's that last listener type, I think, who still bleeds ink straight from the composer's pen every time this film rolls. Writer Peter Shaffer and director Milos Forman cannily exploited something the established classical industry has never quite mastered. The ability to talk about the music while it is happening opens passageways into the mechanics of music in a way rarely experienced beyond the conservatory walls.

The Philadelphia Orchestra's LiveNote project comments on the music via handheld device in real time. But not with heart. Not with the same personal urgency F. Murray Abraham does in that luxurious scene where he is distilling meaning from sound as we hear part of the "Adagio" from Mozart's Serenade for 13 winds, the "Gran Partita." Antonio Salieri, presented ostensibly as Mozart's composer rival, calls it music filled with such longing that it seems he is hearing the voice of god.

The combined spell of music, words, and Abraham's emotional shading isn't something you get over easily, and it comes more than once in this movie. Near the end, when Mozart, too weak to write (but not to be a genius), is dictating the Requiem to Salieri, we get the music delivered in pieces, part by part, and then put together. Would that more live orchestra concerts do that for listeners.

The Philadelphia Orchestra has become fixated on movie music lately — music, that is, like E.T. and Harry Potter, not meant for the concert hall, but brought into it. This live-orchestra Amadeus format, ironically, uses music that lives mostly in the concert hall, but the effect ends up being less powerful than the music of wizards and aliens.

The reason is just this: John Williams is big, high-impact music that surrounds you and is music you may have overlooked before. Mozart here is a combination of live and recorded sound fed through speakers. The orchestra is live, the sound of the opera soloists emanates from the soundtrack; the piano soloist (Curtis student Michael Davidman) is live. The chorus, a very live Mendelssohn Club of Philadelphia, was plenty strong, but not any more vivid than it would have been on speaker via the soundtrack.

And how much could conductor Richard Kaufman contribute hemmed in by the pace of celluloid? His seems a thankless subspecialty of art.

It was impressive, though, to hear the ensemble change form quicksilver: a wind ensemble one moment, an opera orchestra the next. Still striking is the scene where Salieri is thumbing through the scores Mozart's wife has brought for him to consider, and staggering genius streams into the ear: the great peace of the Concerto for Flute and Harp, the incredible momentum of the Symphony No. 29, the Sinfonia Concertante for violin and viola in all its concentrated richness, and on and on. Frustratingly, each one was just a snippet.

It might have been nice for the orchestra to meet the pent-up need to hear these pieces in their entirety later in the season's schedule. As it is, there are a Mozart symphony, two piano concertos, and the quintet for piano and winds. Not bad, but for Mozart still a tease.

Amadeus live with the Philadelphia Orchestra

Performances Friday and Saturday at 7 p.m. in Verizon Hall at the Kimmel Center, Broad and Spruce Streets.

Tickets: $40-$105 (no $10 rush tickets available).

Information: 215-893-1999 or www.philorch.org.