Clay Christiansen and Brian Mathias — the oldest and newest Mormon Tabernacle Choir organists, respectively — were sitting in a conference room in the Tabernacle basement, chatting amiably about how they came to be where they are, literally and metaphorically.

Christiansen recalled with distinct clarity that he was appointed to his position Sept. 15, 1982. Mathias, the man hired just weeks before to take over Christiansen’s spot when he retires in April, shook his head in disbelief upon hearing that date.

“That was nine months before I was even born,” Mathias said.

The musicians’ time as colleagues will be brief, their overlap a temporary arrangement intended to give Mathias time to acclimate before Christiansen steps away from the Tabernacle roster of three full-time and two part-time organists.

And though the veteran confessed he is still adjusting to the idea of his impending retirement, he acknowledged he is also eager to hand over the keys — as it were — to his successor.

“It’s kind of a changing of the guard — a guy who’s been here forever is leaving, and a guy who we really wanted is coming in,” Christiansen said. “He’ll help take things to the next level.”

There are, of course, inherent differences between them beyond merely the 69-year-old Christiansen being on the way out and 34-year-old Mathias on his way up.

The former was born in Emery, Utah, in 1949, a precocious musician who eschewed playtime for practice time, and who dreamed of having this job from a young age.

“I always loved music. And somehow I was always particularly drawn to the sound of the organ, and to the sound of a choir, and particularly to the sound of the Tabernacle Choir, from the time I would hear it over the radio and occasionally over TV, as a boy,” Christiansen said. “It was always top of the mark for me.”

(Leah Hogsten | The Salt Lake Tribune) "It's a kind of changing of the guard," said Clay Christiansen, who began his career as organist for the Mormon Tabernacle Choir in1982 and is set to retire after 2018's Spring LDS General Conference. Christiansen is pictured at the Mormon Tabernacle Choir's organ,Thursday, March 1, 2018.

Mathias, meanwhile, is a Minneapolis native who, as a preteen, was angling to quit those piano lessons he’d been signed up for but detested.

At one point, his mother, tired of shelling out money for lessons he was determined not to follow through on, resorted to fining him a dollar for every day he did not practice.

“My family likes to remind me that when I was about 10, we were on a family vacation out here and they brought me to a recital here … and I was not impressed. I just thought it was the most boring thing,” Mathias recalled with a laugh. “… To my mom’s eternal credit, she wouldn’t let me quit.”

Three or four years later, his new piano teacher — Larry Blackburn, an organist at Salt Lake City’s First Presbyterian Church — offered Mathias organ lessons, which “turned me around in a hurry.”

In reality, the two men have plenty in common. Both have earned doctorates in music, both have worked as teachers, and neither originally considered becoming a Tabernacle organist a realistic possibility.

Christiansen, who, with his wife, Diane, has 13 children, noted, “With a large and burgeoning family to support, I certainly was more practical than to assume that someday I might have that source of employment.”

(Leah Hogsten | The Salt Lake Tribune) "This was a dream come true that I never thought was ever actually going to happen, " said Brian Mathias, who was hired in January 2018 to become one of four full-time organists for the Mormon Tabernacle Choir. Christiansen is pictured playing the Mormon Tabernacle Choir organ, Thursday, March 1, 2018.

Mathias, meanwhile, conceded that even as he became infatuated with organ playing in general, and the Tabernacle organ specifically, to the point of collecting recordings of performances, “I was so far away from all of it at that point, it never seemed like something that was even possible. But, as it turns out, it was.”

True enough.

He saw an online posting for an opening last May. He applied, then was asked to submit recordings of solo repertoire and choral accompaniment. Then, in October and November, he and three other finalists were run through two-day auditions at Temple Square that included sight reading, transposition, ear tests, interviews, piano playing, improvisation tests and, finally, accompanying the Mormon Tabernacle Choir in a 45-minute rehearsal.

Six weeks later, he was in the middle of giving an organ lesson at Brigham Young University when his phone rang, displaying a Temple Square number.

“I got off the phone and I thought, ‘Did that really just happen?’ ” he said. “… I’ve spent the first few weeks pinching myself a little bit. Every time I’d walk up through the front door, I couldn’t believe it.”

Mathias would be well-served to maintain that sense of wonder, Christiansen said.

The Tabernacle organ is so unique and so full of possibilities that “never do you get all the theoretical, as well as practical, combinations figured out.”

Even after 35-plus years of playing it, Christiansen still has the capacity to be surprised by it.

“It took at least a year or two before I had in my head what kind of a sound was going to come out if I pulled a certain stop. And you kind of have to get to that point before you can begin to master a particular instrument,” Christiansen said. “And I don’t know what it means to ‘master’ an instrument, anyway. If you think you’ve mastered it, you probably ought to quit. The exciting possibilities and the wonder of it all must be there in order for the music to touch souls.”

Which brings up yet another insight the two share: They realize that when they’re sitting center stage at the organ, the choir on one side and the Orchestra at Temple Square on the other, there is no better seat in the house.

Though Mathias has had limited time in such circumstances, it nevertheless already has made a massive impression upon him.

“You’re just enveloped in it. So to sit right there and be a part of what’s going on, that’s an amazing feeling,” he said. “It’s really a thrill.”

Christiansen couldn’t agree more.

“It’s a perspective tonally, aurally that no one else gets. I don’t know how to describe it — it’s stereo on steroids,” he said. “But it also is just so surrounding and so heavenly, particularly in an ethereal number. And I thought, ‘I don’t want this to end. I want to remember this sound.’ Because, likely, never again will I hear that.”

Christiansen initially had intended to stay on until he turned 70, but “I was prompted to retire about a year earlier because of the health challenges of my wife. She needs me.”

And though he won’t be stepping away 100 percent — the Tabernacle frequently hosts guest organists, including “retired” former full-timers — he’s still getting used to the notion that the official end is near.

“I have started, actually, to come to terms and to feel comfortable with it — though I still run the gamut of feelings and emotions. Sometimes I think, ‘Ahhhh, I’m gonna miss this.’ I can get emotional after sitting up there and playing my beloved Tabernacle organ,” Christiansen said. “… So, golly, it’s been a special joy to be here at the Tabernacle.”

Mathias certainly appreciates the role Christiansen has played through the years.

They met more than a decade ago when Mathias, as a 23-year-old junior at BYU, was auditioning at the LDS Conference Center for a guest organist spot — a tryout he described as “terrifying.” Christiansen was the first potential judge to arrive, and “he was just so kind and welcoming — he just put me at ease. And he has been that supportive ever since. He’s just been so kind to me over the years. And I always appreciated that.”

Their relationship was cemented further a few years ago when Mathias, checking his office mailbox at BYU, discovered “an envelope from Clay with a new set of hymn arrangements that he had just published. … And he had dedicated one of the pieces in the collection to me. Just out of the blue. Where I was at the time, that made my day.”

For his part, Christiansen believes Mathias is the perfect person to take over for him.

“His playing is not only virtuosic, which you would expect, but also he plays with sparkle and with originality, with interest, which is what our listeners desire, and they have to have,” Christiansen said. “… Despite all of the possibilities with organs, they can be darn boring if there isn’t sparkle and originality there. And heart. And he plays with heart.

“And that’s what we’re all about — uplifting souls,” he added. “… In this hectic and divisive world of ours, the sound of uplifting and comforting and inspiring music is needed more than ever.”

(Leah Hogsten | The Salt Lake Tribune) "It's a kind of changing of the guard," said Clay Christiansen, who began his career as organist for the Mormon Tabernacle Choir in1982 and is set to retire after 2018's Spring LDS General Conference. Christiansen is pictured at the Mormon Tabernacle Choir's organ,Thursday, March 1, 2018.