Camilla Nylund: Voice of the water spirit Rusalka.

Finnish-born soprano Camilla Nylund knew two things about Cleveland before she arrived here last week: First, the city is home to one of the world's greatest orchestras; and second, we have a lot of people who — in the Cliff's notes version of the story — can't afford their houses. As Clevelanders know maybe better than people who live anywhere else, that's the thing about cities and operas: They become known for little bites of their substance, fragments rather than the whole. And while those fragments may be in themselves richly detailed triumphs or tragedies, they don't come close to telling the whole tale.

Nylund will no doubt gain a deeper understanding of Cleveland during her first visit to this Rust Belt city, and she's going to return the favor in music. She's here to sing the title role in Dvorak's opera Rusalka this week with the Cleveland Orchestra. In the same way that just about everyone has heard the "Habanera" from Carmen, and the "Queen of the Night" aria from The Magic Flute, even if they don't know the rest of the works those highlights are extracted from, much of the classical music world is familiar with the "Song to the Moon" from Rusalka. It's the searching lyric in which the beautiful water spirit named in the title asks the moon who will be the love of her life, and even to pass on the message that she is waiting for him with open arms. The song is rich in emotion and longing, its lush harmonies full of color and begging for vibrato. It's a hit-single example of the romantic, pastoral nationalism for which Dvorak and his elder countryman Bedrich Smetana are so beloved. The popular aria has been not only a signature piece for the great American soprano Renee Fleming, but its level of popularity is such that the pop singer Sarah Brightman has even recorded a version.

Beyond the "Song of the Moon," though, Rusalka is not well known in the US, or for that matter, much outside Czechoslovakia, because the Czech language is a challenge even for notoriously polyglot opera singers. In 30 years, the Cleveland Opera never took it on. When Nylund sings the piece this weekend at Severance Hall — a concert performance of the whole opera — it will be the first time ever for the Cleveland Orchestra. And if the "Song to the Moon" is a hit single, the entire opera is a mega-dose. Music director Franz Welser-Möst, will conduct the season finale performances. Besides Nyland in the title role, the cast includes tenor Piotr Beczala as the Prince, soprano Emily Magee as the Foreign Princess, bass baritone Alan Held as Vodnik, mezzo soprano Birgit Remmert as Jezibaba, and members of the Cleveland Orchestra Chorus. English surtitles above the stage will enable non-Czech speakers in the audience to keep up with the action.

EVEN IN EUROPE, Nylund says, Rusalka is not often performed. She's sung the "Song to the Moon" before and has seen a performance at the Vienna State Opera, but this will be her first performance of the whole opera. Welser-Möst had asked her to sing the role for the Cleveland Orchestra's performances at the Saltzburg Festival in August, which he will also conduct. According to Nylund, the maestro said since the Dvorak opera was new to both her and the orchestra, it would be a good idea to perform it first in Cleveland before taking the opera to the Saltzburg Festival.

Dvorak's best-known opera, Rusalka has something in common with the Hans Christian Anderson fairy tale The Little Mermaid: A water spirit wants to experience human love, but has to give up her immortality to do it, and even then risks damnation. She thinks it's worth it, though, and even if he is skeptical, her father agrees. But, as Nylund observes, the opera doesn't have a happy ending. They wander a road of jealousy and torment before confirming their love in a kiss. He dies, and she is condemned to dwell for eternity as a spirit of death in the depths of the lake.

"That's what opera is," the soprano says. "Or maybe it is a happy ending, because they reach another dimension."

Nylund says the role is challenging because it demands comfort in a range of singing styles. "You have very lyric parts, but you also have to be dramatic. It has a big, big range." But the bigger hurdle for most accomplished singers is the language. Having grown up in the Swedish-speaking town of Vaasa, Finland, she speaks Swedish, and is also fluent in German and English. But she doesn't speak Czech. Idiomatic translation is never word by word, and especially in something as poetic as an opera, it inevitably changes the placement of the emotional punch. As if that weren't enough, there's the challenge of getting the sound just right.

"You have to of course work on the language the whole time. As a singer you try to copy the sound. It's not enough to do it five times." She's had help from the Czech-born vocal coach Susan Jay, who, coincidentally, also coached Renee Fleming for her performances of Rusalka. She says one sound is particularly elusive.

"It's a kind of hapchik "R' with a sign on the top [she makes rolling R noises]. You have to sound like, "Rrrrr.' I grew up speaking Swedish, which also has a rolling "r,' but this is a special kind of rolling. It's more airy."

Only a few Czech speakers in the audience will be privy to that level of nuance. The rest of us will just have to be content with the music itself. Poor us.

Rusalka w/ the Cleveland Orchestra: 7 p.m. Thursday and Saturday at Severance Hall, 11001 Euclid Ave., 216.231.1111.