December 13, 2012 | JACK WALTON | South Bend Tribune Correspondent

For the first and last songs of Sunday’s “Christmas at Loretto” concert, the South Bend Chamber Singers will encircle the audience, singing from all corners of the richly reverberating Church of Our Lady of Loretto on the campus of Saint Mary’s College. The voices will interweave in the air, picking up the room’s natural sustains and echoes, creating a luxurious sonic experience for lovers of choral music.

The opening work, Norwegian composer Ola Gjeilo’s “Prelude,” was designed as entrance music, and has a suitably invigorating presence to it. It also features many long-held notes, which should show off Loretto’s acoustics splendidly.

Another piece by Gjeilo, “Serenity (O Magnum Mysterium),” is a showcase for guest musician Carol Bullock Russell, who contributes cello accompaniment to three pieces in the concert.

“That piece is very slow and sustained,” Chamber Singers music director Nancy Menk says. “It just unfolds. We’re actually sort of accompanying the cello part. He treats the cello like another voice. It’s like another voice in the choir, but with a different timbre.”

“The lowest tones on the cello are like a low male voice, and the really high stuff is like a soprano,” Russell says. “I think that resonates with people, and that’s why I think the cello lends itself to combining with choral music.”

A resident of South Bend for 20 years, Russell recently moved to Kalamazoo, where she plays in the Kalamazoo Symphony Orchestra. She also joins the singers for Kenneth Jennings’ “What Sweeter Music Can We Bring,” a setting of a poem by Robert Herrick.

Russell says the piece is rhythmically varied, with prominent use of mixed meters.

Menk could easily trot out a roster of holiday favorites, but she’s committed to exploring the contemporary repertoire, including Sunday’s world premiere of British composer Bob Chilcott’s “Gifts for the Child of Winter,” commissioned by Menk.

“I never want anybody to feel threatened — ‘Oh, I don’t want to hear a bunch of new music’ — so I make sure it’s really beautiful,” Menk says. “At Christmas, people want to hear some tunes they know, so I always include new arrangements of familiar carols. The arrangements are interesting and challenging for the singers, but people will still recognize them.”

Beloved anthems and carols in new guises at this year’s show include “Lo, How a Rose E’er Blooming” and “Veni, Veni Emmanuel.”

Fans of Peter, Paul and Mary will recognize “A-Soalin’,” which the trio released in 1963 on the album “Moving.” Menk has selected a more recent arrangement by Ronald Staheli.

Many of the lyrics refer to the roaming carolers on All Souls’ Day in England, who beg for flat cakes. In exchange, they promise to pray for the donors and their families.

By the end, “A-Soalin’” ascends to a dense level of complexity, and this performance will have for its foundation a bass line in Russell’s cello, while Kathleen Keasey plays reed stops on the organ.

The Chamber Singers reconfigure into their initial positions around the edges of the church for the concluding “Silent Night.” Menk favors the arrangement by Sir Malcolm Sargent over simpler versions of the song. Sargent exposes some pungent harmonies, making for a cerebral “Silent Night,” rather than a merely sentimental one.

“Sometimes people will start to sing along,” Menk says, “and then they’ll realize, ‘Oh wait. I don’t know this version. Maybe I’ll just listen.’ ”