Moviegoing is, at times, a quest for that moment when reality suddenly makes unexpected sense. And it was during a screening of the 1920 German Expressionist silent film, “The Cabinet of Dr. Caligari,” that Matthew Nolan had one such moment. An amateur musician and budding film scholar, Mr. Nolan suddenly saw a creative path for himself.

“Seeing the film made me realize that the possibility existed not only for musical but for sonic exploration,” Mr. Nolan, who is based in Dublin, said. It wasn’t too long before he began collaborating with an assortment of musicians to create live soundtracks for “Caligari” and other masterpieces of the pre-sound era. The result was the invention of a fresh way of “hearing” silent film — one that had little to do with traditional forms of accompaniment.

Mr. Nolan, who plays guitar, is now the head of the septet known by the unusual name 3epkano (three-epkano), which performs live during silent films. The band has created musical accompaniment for 11 films and 12 shorts during the past four years, with a special focus on German Expressionist masters such as F.W. Murnau, Fritz Lang, and G.W. Pabst, whose “Pandora’s Box” gave the band an occasion for its American debut last year at the Brooklyn Academy of Music’s BAMcinématek. The group returns this week for shows at BAM, where it will perform with Murnau’s “Sunrise” tomorrow night, and at the Film Society of Lincoln Center, where it will accompany Paul Leni’s “The Cat and the Canary” on Friday night.

“There’s a psychological depth to those films that isn’t there in later American films of the silent era,” Mr. Nolan said. The affable Irishman was enjoying a pint of Czech beer at a café adjacent to BAM on a recent afternoon, having arrived a few days ahead of his bandmates to enjoy some tourism and a favorable exchange rate. “Sometimes people forget about the Russian formalists and the German Expressionists. The teens and ’20s were such a vibrant era for filmmaking, for visual exploration. And someone like Murnau was at the peak of that. No one can rival him for telling a story through images.”

“Sunrise,” with its saga of obsessive love, betrayal, loss, and redemption, works perfectly with 3epkano’s genetically Irish sensibilities. The 1927 film was Murnau’s first effort after he abandoned Germany for Hollywood the year before: It is a parable about The Man (George O’Brien) and his Wife (Janet Gaynor), and the scheming Woman From the City (Margaret Livingston), who convinces the husband to kill the missus so that they can continue their affair. But fate intervenes in several unexpected ways, and The Man comes to both cherish his wife and profoundly regret his intentions.

“A sense of tragedy that permeates all of Murnau’s work is at its most acute in ‘Sunrise,'” Mr. Nolan said. “It’s a much more personal kind of narrative. There’s always some kind of fall from grace taking place. Here is a simple [marital] relationship challenged by an outside force, and the melancholia that arises from that dramatic tension suits us very well. The music we write a lot of the time is quite mournful.”

The band’s instrumentation, which includes cello, viola, bass, electric guitars, and keyboards, also is flexible enough to swing between minimalist chamber music and experimental rock instrumentals. As documented on the band’s albums, such as “On Land,” and MP3 files on the Web site of its record label, Smiling Politely, the group conjures imaginary landscapes with sensitive feel and haunting imagination. They are hardly alone in their endeavors. Jazz and rock performers, especially, seem to enjoy performing with movie projections as a diversion from routine. But few make a personal mission out of it.

On its MySpace page, the group cites the idiosyncratic, all-instrumental bands Dirty Three and Mogwai, as well as less-heralded originals such as the New England singer-songwriter Chris Brokaw. The musicians’ ambient approach insists on a lot of breathing room. “We let the film conduct us,” Mr. Nolan said. “We try to create music that doesn’t underscore action the way a lot of silent film scores do. They’re almost relentless, with the pianist hammering away for 80 or 90 minutes.”

When starting to compose new music for a film, the bandmates absorb the character and flow of each film through multiple viewings. And during performances, they are attentive to the screen itself — rather than their sheet music — so that any performance will have its own unique improvisatory flourishes. Fortunately, Mr. Nolan said he doesn’t flinch from mistakes that naturally occur during a gig. “When we did ‘Pandora’s Box’ here last year, I remember messing up one particular cue, and it was a cue where our two string players had a piece worked out for about two and a half minutes,” he said. “And I kicked in. I wasn’t supposed to start for three minutes. But we made it work. When you’re not overly hung up on letting the action dictate the music, then you create something.”

All of which keeps the band enmeshed in the moment and in service of the film — unlike other artists: “You can see people with their time codes and the music and they aren’t even watching the film,” Mr. Nolan said. “For us, there’s a reverie there.”

That sense of give-and-take with the film is something Mr. Nolan has found absent in high-profile endeavors he has witnessed as an audience member. “Philip Glass was in Dublin once as part of the theater festival with the Kronos Quartet, and they did ‘Dracula,'” he said. “It’s absolutely beautiful music, but it didn’t always cohere and sometimes there was too much of it. But the aspect I found really disturbing was that during moments of high drama, a backlight would come on behind the musicians — who were playing behind the screen — so that you became aware of the musicians and what they were doing. That was incredibly egotistical.”

Mr. Nolan and his crew hope to fade from the audience’s perception during the flick. “The best compliment we can be paid is that people forget we are there and get sucked into the picture, unaware that seven people are maniacally trying to perform.”