There's nothing particularly Mormon, or American, about "Ubi Caritas." It's a Gregorian chant at least 11 centuries old that was rearranged by French composer Maurice Durufle in 1960 and has been sung by church choral groups around the world.

But I can tell you that when it’s performed by a certain famous choir in a certain quirky old building in downtown Salt Lake City, that melody works a particular magic.

The voices rise and fall, singing a cappella in Latin. The sound ripples to the back of the hall, guided by the curving plaster ceiling. The final "amen" grows to 10, 15, 20 syllables, each one a slow-motion acrobat in flight.

That's how it went on a recent Sunday morning at the Salt Lake Tabernacle at Temple Square, a singular American music venue commissioned by Brigham Young and completed in 1867.

The 360 singers are now known as the Tabernacle Choir at Temple Square since Oct. 5, when leaders of the Church of Jesus Christ of Latter-day Saints changed the name from the Mormon Tabernacle Choir.

In Salt Lake City, Utah, an aerial view of the Temple, Visitors Center, Tabernacle, and Conference Center on Temple Square.
In Salt Lake City, Utah, an aerial view of the Temple, Visitors Center, Tabernacle, and Conference Center on Temple Square.

As for the building that houses them, one unimpressed 19th century visitor called it “a pumpkin half-buried in the sand.” To me, as light danced on its aluminum roof (a 1947 addition), the tabernacle looked like a surfacing submarine.

That shiny roof is a great disguise for a frontier relic and a striking element among the landmark church buildings that make up Temple Square.

The history is more than enough reason to eavesdrop on choir practice (most Thursday nights) or to see a broadcast performance (Sunday mornings) or to drop by to hear a pin drop (hourly from 9 to 9 to show off the hall's acoustics).

A Thursday night rehearsal in the tabernacle, free to the public at 7:30, is a good place to start.

Once you're inside, look at the choir loft, where members will be meandering to their assigned seats, men on one side, women on the other, and making notes on their sheet music.

Music director Mack Wilberg probably will be up front with a microphone, delivering corrections and commendations with a dry wit: "Ladies, you sound great. Men, you've got to listen more to the ladies."

In Salt Lake City, Utah, Tabernacle Choir singers take a snack break just before their usual Sunday broadcast performance at the Salt Lake Tabernacle at Temple Square.
Christopher Reynolds / Los Angeles Times / TNS
In Salt Lake City, Utah, Tabernacle Choir singers take a snack break just before their usual Sunday broadcast performance at the Salt Lake Tabernacle at Temple Square.

To win a place in this choir, singers must belong to the church, be at least 25 and no older than 55 and live within 100 miles of Temple Square. Besides an audition, they must pass an interview and music theory test.

For the 20 percent of applicants who make the grade, there are hundreds of songs to learn and a year-round schedule of rehearsals, broadcasts, and performances and sometimes recording sessions and tours. Once choir members have sung for 20 years or have reached the year of their 60th birthday, they’re excused and replaced.

Oh, and there is no paycheck.

All choir members are volunteers, as are the 110 members of the orchestra. Administration and logistics are handled by a general manager and a paid staff of about a dozen.

When the choir was formed under church president Young in 1847 -- less than 20 years after the church’s founding by Joseph Smith in upstate New York -- Mormon pioneers had just begun settling in Utah, and the Salt Lake Valley was nearly empty. Before long, Young was planning a tall, stone temple (which took 40 years to complete) and the tabernacle (which would be made of Utah pine, about 75 feet tall, 150 feet wide, and 250 feet long, capped by a gently curving roof).

Young worked with local architects and a bridge designer to craft one big room with uninterrupted sightlines and lively acoustics so a preacher's voice could carry. That meant thinking outside the architectural box.

Young eventually chose an oval design, the roof held aloft and shaped by wooden lattice truss arches and held together by nails, bolts, and wooden pegs above 44 stone piers. Builders painted pine columns to look like marble and disguised pine benches to look like oak. (In the last 20 years, the church has replaced most of the pine benches with oak.)

And there is the organ, with 11,623 pipes, that towers behind the choir loft like the bow of a great ship. It isn't the original but a descendant of one built in the 1860s, using hardware from Boston and pipes carved from more Utah pines.

"Sit in the front row and you hear the music hit you right away," says Stephanie Wood, an alto who is an 18-year choir member. "You sit in the back row and it feels like it wraps around the building before you hear it."

In the choir loft, she says, there are spots "where you can't hear really at all. You sit there and you think, 'I'm singing by myself.' "

The building "oozes history," says Matt Harmer, a 54-year-old attorney and father of seven who started singing baritone with the choir in the last year. The first time he stood in the tabernacle to sing "Come, Come Ye Saints," a hymn from the church's early days, “was very emotional, just to have a chance to sing this song that has meant so much to so many people in this faith, in this building that people sacrificed so hard to build."

“Music & the Spoken Word” — a 30-minute melange of song, organ music, and inspirational narration — began as a radio show in 1929. By 1949, the choir was releasing its first commercial album on Columbia Records. By the 1960s, the broadcast was televised, and the choir was singing for presidents, touring the world, and working with the New York Philharmonic and the Philadelphia Orchestra.

More recent collaborators have included Audra McDonald, Yo-Yo Ma, James Taylor, and, for the just-completed holiday shows, Kristin Chenoweth.

On my Sunday morning, men wore dark suits and ties and women beige gowns. The benches, typically arranged to hold as many as 3,000 listeners, were about two-thirds full. After the countdown to open the broadcast, a narrator welcomed us and organist Richard Elliott leaned over the keyboards.

A sophisticated lighting system threw intense colors onto the curving wall behind the choir — sometimes blue, sometimes purple, sometimes red, which made the gold-leaf organ pipes glow like flames.

Several hymns, folk songs, and other pieces followed, including "Ubi Caritas." Edgy it was not. But those 360 voices, raised together, were something to hear.

In no time, the broadcast was winding up. It ended with the choir’s voices on “God be with you till we meet again” — warm and comforting on a winter day.

The Tabernacle, usually open 9 a.m. to 9 p.m. daily, is part of Temple Square, a 35-acre area that includes the Salt Lake Temple among many church buildings (including two visitor centers offering free tours). The Tabernacle offers choir rehearsals (7:30 p.m. Thursdays), rehearsals for Bells on Temple Square (7:30 p.m. Wednesdays); daily half-hour organ recitals (noon Mondays to Saturdays, 2 p.m. Sundays); and live broadcasts of the choir’s 30-minute “Music & the Spoken Word” program (8:30-10 a.m. Sundays). Schedules are subject to change.