It’s the same old story: Girl meets boy. Girl falls in love with boy. Girl hopes to marry boy. Girl is unfortunately unaware that boy is in fact already wed — and also that boy is actually a disguised noblewoman who has infiltrated the prison overseen by girl’s father in order to rescue her husband, who is being held as a political prisoner in the lowest levels of the prison dungeon.

So begins “Fidelio,” the only opera ever written by Beethoven. North Coast audiences will get the chance to experience “Fidelio” in person this Sunday, Sept. 21 when Eugene-based Cascadia Concert Opera brings the work to the Clatsop Community College Performing Arts Center in Astoria. The performance is a benefit for Partners for the PAC, a group that works to maintain the building as an arts center.

Rather than a fully-staged opera, “Fidelio” will be performed as a concert opera, a less-formal version of the work. Jan Nelson, co-founder of Cascadia Concert Opera, explains that concert operas often give audiences a more intimate experience.

“For us, (a concert opera) typically means that there are no sets, there are limited costumes and props, and that most often we use the score, so we have sheet music in our hands that we’re reading from,” Nelson says.

Audience members get to watch the characters interact on the stage in a smaller setting than might be possible with a fully-staged production.

“We’re right in their face so they can experience the huge power of the voice and really share an experience with the performers,” Nelson says. “There’s no particular way (audience members) have to act … no particular way to dress. We want people to actively take in our performances as much as possible.”

In another effort at accessibility, the opera will be performed in English instead of the original German. According to Nelson, “with opera, there is an inherent understanding of many things” through music and expression. “But to really get the intricacies of what’s happening,” she says, “we don’t want our audience members to feel like they have to work too hard to get it.”

Cascadia likes to provide opportunities for local singers, and the group has enlisted area talent to play important parts in “Fidelio.” The North Coast Chorale will be the chorus of prisoners, and a leading role — that of Rocco the jailer — will be played by local singer and CCC instructor Deac Guidi.

“This is a dream role at this point,” Guidi says. “It’s so good, and it’s a big, meaty kind of part.” Because of his bass-baritone voice, Guidi explains, “most of my characters are either fathers or idiots, or the really, really bad guy. So this is really nice; this is more of a father role.”

Carol Smith, who will sing in the chorus and also works with Partners for the PAC, emphasizes the importance of events like this one for the continued survival of the Performing Arts Center. “There are people who love the PAC because it’s part of their own history and people who love the PAC because we perform there,” Smith says. “Nothing matches the sound at the PAC. It’s an important asset to the community.”

About “Fidelio,” Smith says, “It’s the triumph of married love; the music is beautiful.”

Guidi goes a step further. “It’s Beethoven’s only opera, so it’s cool to sing it,” he says. “One of the singers called it ‘Mozart on steroids,’ which I think is perfect because it’s like Mozart, but about 700 times louder.”