If you think you know “It’s a Wonderful Life” forward and backward, you’re about to get a chance to experience a new facet of the holiday classic.

When the Chicago Symphony Orchestra performs the movie’s soundtrack Dec. 9-11 as the film is projected above the stage, it will feature 40 minutes of music written by composer Dimitri Tiomkin that were cut from the movie’s original 1946 theatrical release. Tiomkin, an eventual four-time Oscar winner, had scored Frank Capra’s “Mr. Smith Goes to Washington” (1939) and received his first Academy Award nomination for that movie. Though “It’s a Wonderful Life,” directed, produced and co-written by Capra, initially bombed at the box office, over the decades, it found an international audience and secured its reputation as a cinematic masterpiece. Its theme of redemption, as a disheartened businessman (James Stewart) discovers that every life has meaning, gains even more resonance at the holidays.

Composer-conductor Justin Freer

Composer-conductor Justin Freer

Now “It’s a Wonderful Life” “is glorious in a whole different way with the score restored,” said composer-conductor Justin Freer, who found Tiomkin’s printed score in the Paramount Pictures archives. The founder and president of CineConcerts, a company dedicated to concert presentation of film music, Freer also prepared the performing version, which he will lead at Symphony Center.

Freer theorizes that Capra made the cuts to Tiomkin’s score to lighten the movie’s mood, leaving the popular dance music intact. (For instance, “Buffalo Gals,” the tune most people associate with the movie, existed in at least 12 different versions at the time.) The decision led to a feud between the director and composer that was not resolved for several years, Freer said.

The orchestra also will be playing the dance band music from the famous scene that ends with James Stewart and Donna Reed in the pool, and the Chicago Symphony Chorus will join in a few scenes, including blending with the actors’ voices in the final “Auld Lang Syne.”

As originally envisioned by Capra, “It’s a Wonderful Life” was a downbeat drama about the disappointments confronting post-war America. RKO Pictures, the distributor for Capra’s independent Liberty Films, decided instead to capitalize on the movie’s holiday subplot, and changed the movie’s release date from spring 1947 to Christmastime 1946. “Since the film was already shot, its flavor had to be changed by altering its post-production values,” said George Harter, retired host of the radio series “A Night on the Town,” in a post for the site Sharing from Fans & Friends (maintained by Karolyn Grimes, who played Zuzu in the film). “A film’s music is the major factor in setting tone and atmosphere, and Tiomkin’s music was too somber and dark for the film’s new approach. His work was cut heavily, music was moved within the film to places where Tiomkin did not intend it to be, and the work of other composers was even inserted in places.”

Dimitri Tiomkin

Dimitri Tiomkin

It took the work of Freer and other classic-movie soundtrack enthusiasts to restore Tiomkin’s score to its intended state.

For the CSO concerts, the musicians will work without a click track. It is common in live film concerts to see every musician wearing headphones, which transmit a metronome beat to help keep the music in sync with the images on the screen. Freer, however, thinks that performing without that safety net yields “a much more musical performance. That’s how we train. We don’t learn to breathe with a clicking in our ear.”

Instead, Freer conducts with a small screen on the podium, showing him what the audience sees, plus visual cues for the music. “It’s no less accurate,” he said, “and the difference is that the music arrives at the same point in a more organic way.”

It does, however, put more pressure on the conductor. “I never thought I would welcome the ease of conducting opera,” Freer said, laughing. “Everything else is stress-less in comparison. It’s a wonderful stress — but there are more things you have to focus on.”

Most people may not have strong memories of the background music to “It’s a Wonderful Life,” but “it’s amazing how a great score can go unnoticed,” Freer said. Moviegoers often will leave the theater remembering the emotions they felt, but often not realizing that the music made them feel that way.

Film music is “up there with symphonic structure, opera structure, ballet structure,” Freer said. He has studied, loved and conducted all of those forms, but for the moment, his niche is in live performance of movie scores. Many more orchestras have begun programming such events in the past few years. Freer thinks it’s both a recognition of a new audience for symphonic music and an acknowledgment of the role that film plays in modern culture.

Freer’s CineConcerts is currently working to produce live performing versions of all eight “Harry Potter” movies. Beyond that, “I have a really long bucket list,” he said. “I adore the Golden Age of Hollywood.” But the live version of “It’s a Wonderful Life” is “something you do have to see to believe. You can’t experience it anywhere else.”

David Lewellen is a Milwaukee-based journalist.