"La Pasión según San Marcos" is such an epic work — performed so rarely — that if Ahmed Anzaldúa had heard about it being staged in Los Angeles, he would have flown there. No question.

So the fact that it's being performed here in Minnesota is exciting. The fact that Anzaldúa is preparing the chorus for this weekend's performances?

Exciting and terrifying.

"I haven't slept much in the last week," he said.

For two months, Anzaldúa, a Minnesota-based, Mexico-born choral conductor, has been prepping Minnesotans to sing Argentine composer Osvaldo Golijov's theatrical reimagining of the Bach Passions, a 90-minute piece steeped in Afro-Cuban, Brazilian and other Latin American musical styles.

"La Pasión según San Marcos," or "The Passion According to St. Mark," has only been staged some 54 times — almost always by the Venezuelan choir that premiered the work in 2000: Schola Cantorum de Venezuela. Twenty-five members of that choir were supposed to trek to Minnesota, pairing up with singers of the Minnesota Chorale and Border CrosSing to perform with the Minnesota Orchestra on Friday and Saturday. But because of the crisis in their country, the singers couldn't get the passports and visas required to travel here for the crowning concerts of this year's Sommerfest.

So Minnesota singers are stepping in, along with nine Schola alumni who now live in the United States. The cast, which also includes dancers, string and brass musicians and a bevy of percussionists, will be led by María Guinand, the renowned Venezuelan conductor who knows "La Pasión" better than anyone — partly because she helped create it.

But for many Minnesotans, it's new territory.

"There's a lot of stereotypes associated with choral music, particularly Minnesota choral music and Lutheran choral music," Anzaldúa said. "It's bland, it's floaty. It's beautiful, it's pretty. But it's a little impersonal, a little mechanical."

Guinand is pushing them into the emotional, physical spaces of this piece, he said. "With María, every one of those 51 singers is a soloist, is an actor. It has such an emotional impact. She draws it out of every person."

The piece was commissioned by the Bach Academy of Stuttgart for the 250th anniversary of Bach's death. Before its premiere to acclaim in Germany, the composer flew to Venezuela to work with Guinand and her singers. Golijov composed during the day and, at night, the choir tried out what he had written. Soloists influenced solos, musicians helped form melodies. "We were like a lab choir for him," Guinand said Tuesday in Orchestra Hall.

The score itself doesn't reflect the scope of the performance, she said. "We are used to doing things in a way that perhaps is not easy to notate." To master the work, musicians must listen to recordings, watch videos. It's almost an opera.

"Sound, music, lighting, action onstage — everything is one piece," she said. "You cannot be doing 'La Pasión' as you would do an oratorio from the 19th century."

Guinand, 66, was disappointed that her choir was unable to travel with her to Minnesota. Doing so would have involved trips to Colombia to obtain visas, she said, as embassies and consulates have exited Venezuela. "We are paying the price of living in a dictatorship."

But arriving at Orchestra Hall last week, she was "extremely happy" about the work Anzaldúa did to prepare the Minnesota musicians on a piece that "belongs, really, to the cultural background of Afro-Latin American traditions," with complex rhythms and uncommon vocalizations.

"They are North Americans, but they understood clearly the philosophy of this piece, the sound," Guinand said. "They're so flexible, so open.

"It's beautiful."

Jessica Colmenares was 11 and living in Venezuela when she first saw "La Pasión" performed. Her mom, an alto, was a part of Schola, so as "the pet, the puppy of the choir," Colmenares traveled with the group to Germany.

"La Pasión" became her "Row, Row, Row Your Boat," she said, laughing. She sang with Schola's children's choirs and, later, performed the piece several times as a soprano.

An opera singer now, she lives in Houston and is among the Schola alumni who traveled to Minnesota for these performances. She was disappointed that her mother, who has sung with Schola for more than 25 years, won't be here, too. They haven't seen each other for four years.

And she was nervous about new singers performing the piece. But when she arrived, she encountered a choir comfortable with the music, the rhythms, the Spanish.

"The difficult part is the acting part, how to connect with the piece," Colmenares said. Once you do, she said, "you feel elevated.

"Something inside is growing inside of you, like light, and you are spreading that light to everybody."

When Anzaldúa, 37, first heard a recording of "La Pasión" back in 2001, "my idea of choral music was the sort of bland thing you listen to in church," he said. Very European music, probably sung in Latin. This piece, which blends salsa and bossa nova, Afro-Cuban and popular Latin American rhythms, "blew up any sort of preconception I had about what choral music was," he said.

Anzaldúa created Border CrosSing, a choir intent on integrating audiences, and for its first concert in 2017, picked a movement from "La Pasión." It struck him that the piece's theme — "the resilience of the Latin American people, their courage and their faith" — was timely then, maybe more relevant now.

It might not seem obvious to explore those themes through the story of Jesus' final days on Earth, with text drawn from the Bible's Gospel of Mark. With the brass of a salsa band. With clave and accordion. But in many ways, the piece is in perfect keeping with Bach's own Passions, he argued.

"If Bach was living in Cuba in 1999, he might have written a Passion that was full of mambos and salsas and santería chants," Anzaldúa said. "It would have been in popular Spanish. There's that real appreciation not just for the craft of music but for its social context and for the way we connect to it."

Jenna Ross • 612-673-7168 • @ByJenna