At the start of Friday night's Philadelphia Orchestra concert, low flutes joined forces with high bassoons, the double basses threatened to do evil, and the violins were constantly trying to warn us to look over our shoulder.

Spooky stuff. So much so, it was hard to pay attention to what was happening on screen.

The big screen, that is.

It was another in the orchestra's increasingly frequent movie nights, this one drawing a good crowd for Raiders of the Lost Ark. The success of the live-orchestra movie format depends not just on how much there is for the orchestra to do, but also whether the audience is getting anything in return for putting down the popcorn to sit in a concert hall.

Raiders of the Lost Ark isn't John Williams' best score. But there's not a lot of downtime for the orchestra, and there was no question that without a live orchestra along Friday night with conductor David Newman, Indiana Jones would not have been half as heroic. We don't need an orchestra to tell us the Nazis are pure evil, but nothing says it with as much edge and acid immediacy as the visceral buzzing of a stopped-up French horn.

The music even saved one scene that hasn't aged so well, and it happens to be the climactic one. When the ark is opened to release deathly spirits, the special effects look unsophisticated, and the movie suddenly seems all of its 35-plus years. But Williams' music here is wondrous, complex and expansive, and the job of appreciating the scene emotionally gets handed over to the ears, and the moment carries.

The orchestra's presence is big, but much of the dialogue was muddy in this presentation, which, even in an action film, was frustrating. The level of inspiration Williams found elsewhere – his Harry Potter music, for instance – is only incipient here, but he is always an evolved craftsman. Sometimes the editing is cut with the music in a thrillingly detailed way. Quiet moments were often the best, when Williams got a stretch of time to set up a transition, or illuminate the interior of a character.

Over and over, the orchestra justified its live presence (although whether it was worth the $40 to $105 per ticket was very much up to each listener-viewer). The music and film made a direct connection here that doesn't happen in a movie house, much less at home – an almost 3-D sensation of image and sound meeting in the air.

Trumpeter Jeffrey Curnow tapped a sweet statement of the main theme. You didn't just see Jones running from the great rolling boulder – you felt it on the back of your neck. Williams made the schmaltz believable in the scene where Marion Ravenwood finally surrenders her moxie for something more lovey-dovey.

The passage of time falls upon film in unpredictable ways, but in the context of today, the scene where Indiana Jones is chasing the Nazis through the desert is striking. He's on horseback, like an American cowboy, while the orchestra plays the most triumphant iteration of the main, march-like theme. The music is so sure of itself, it made you long for a time when the line between hero and villain was so blatant to everyone.

Additional performance: Sunday at 2 p.m. in Verizon Hall, Broad and Spruce Streets. The usual $10 rush tickets are not available for these concerts., 215-893-1999.