If you go

WHAT: Westminster Choir concerts

WHEN: 5 p.m. today, Monday

WHERE: Cathedral Church of St. Luke and St. Paul, 126 Coming St.

COST: $25 and up

MORE INFO: spoletousa.org; (843) 579-3100

As the Spoleto Festival USA has withstood changes in its leadership, its programming and its audiences over 37 years, one crucial and consistent linchpin has been the Westminster Choir.

“Westminster Choir is the first chorus to become a permanent chorus-in-residence,” said Joseph Flummerfelt, the festival’s artistic director of choral activities and the former conductor of the choir. “It starts with me in Italy.”

Invited by the festival’s founder, Gian Carlo Menotti, Flummerfelt first brought the Westminster Choir to the Festival dei Due Mondi in Spoleto, Italy, in 1972. When Menotti established its sister festival in Charleston in 1977, the choir performed in choral concerts as well as operas at both festivals.

This year members of the choir will perform as the opera chorus in the “Mese Mariano” and “Le Villi” double bill, and in “Matsukaze,” an opera based on a Japanese Noh play.

“Almost never in the United States is there a regular choir, like the Westminster Choir, that would become the opera chorus,” said Joe Miller, who has been the conductor of choir for the past seven years. Opera companies typically assemble an ad hoc chorus that doesn’t necessarily sing together generally, he said.

The 40 singers in Charleston for the festival are students from Westminster Choir College, part of Rider University in Princeton, N.J. As a choir with 90 years of history, it maintains its reputation through recordings and concert tours.

Right after the college’s spring break, the choir started to prepare for the festival. The students are divided into two groups — 32 for the Italian operas (seven of whom have specific roles in the first opera) and eight for “Matsukaze.”

In “Matsukaze,” the chorus does more than sing. “‘Matsukaze’ uses a lot of what we called extended vocal techniques,” Miller said. “There are things that are not standard for voice, like making voices of wind and sirens.”

The chorus also plays some percussion while on stage.

“It’s a really challenging project,” said soprano Anna Lenti. “It’s very difficult to memorize. I can’t think of another time in my life when I’m aware of the name of every note that I’m singing at all times.”

The choir singers in “Mese Mariano” and “Le Villi” aim to create characters even when they play nameless roles.

“I don’t have a character here, but I kind of put subtext to two of mine,” tenor Shane Thomas said. “In the first part, I’m somebody who’s going after the girl who’s next to me, and in the second part, I’m somebody who’s very concerned about Anna.”

Rehearsals can be intense: The opera chorus must be completely staged within three days, which can mean nine hours a day of rehearsing. And because Westminster Choir has always prioritized the opera in its Spoleto schedule, the group doesn’t shift its focus to concert music until after the opera is fully prepared. That’s one reason why Westminster Choir usually presents its concerts later in the festival.

“It’s this one big coordinated wave that gets us through the festival,” Miller said. “How that flows is really important to the success of the festival.”

In its concert this evening at the Cathedral Church of St. Luke and St. Paul, the choir will perform a wide range of selections from different cultures and eras, including Benjamin Britten’s “Hymn to St. Cecilia,” young composer Daniel Elder’s “The Heart’s Reflection” and works rooted in different cultures — Latin, German, French and Creole.

“Being part of the Spoleto Festival has certainly been the highlight of the choir for the students,” Flummerfelt said. There are young students in the choir, he said, who have never been on stage in real productions.

“The really amazing thing always is to see students, especially young students, experience that for the first time, being in the costume, makeup and wigs,” Miller said. “It’s pretty extraordinary, for them and for me.”

Xiaoran Ding is a Goldring Arts Journalist from Syracuse University.