Sandy • On an unassuming residential street, in a house where the only clue as to what’s happening inside is the vanity plate on an SUV parked outside, four self-described “Mormon dads from Utah” make chart-topping music and cook up the videos that have drawn 1.8 billion YouTube views (and counting).

The Piano Guys’ headquarters resembles the world’s politest and tidiest frat house — complete with a neat line of water bottles in place of the traditional beer-can pyramid. Posters documenting the group’s international tours fill one wall. A grand piano, specially equipped with a device that stops the hammers just short of the strings so that pianist Jon Schmidt can do his finger-strengthening exercises in silence, dominates the living room. Video cameras are positioned throughout the house to capture musical inspiration whenever it strikes. The four guys — Schmidt, Steven Sharp Nelson, Paul Anderson and Al van der Beek — spontaneously begin whistling the One Direction hit “What Makes You Beautiful” while signing box after box of CD covers around the kitchen table.

Downstairs, one bedroom has been converted to a sound booth with wall-to-wall cellos, while another is filled with recording and mixing equipment. And then there are the hand drums. So many hand drums.

(Francisco Kjolseth | The Salt Lake Tribune) Members of The Piano Guys musical group, including videographer Paul Anderson, pianist Jon Schmidt, music producer Al van der Beek and cellist Steven Sharp Nelson, work on the possibilities for an upcoming show at their home studio in Sandy.

On a recent weekday afternoon, the four friends were getting ready for a month of concerts from coast to coast, including what they consider their centerpiece show Friday at Salt Lake City’s Vivint Smart Home Arena.

Sing us a song, you’re the Piano Guys

The Piano Guys will perform in support of their new album, “Christmas Together.”

When • Friday, Dec. 8, 7:30 p.m.

Where • Vivint Smart Home Arena, 300 W. South Temple, Salt Lake City

Tickets • $24-$114; vivintarena.com/events/318

“Our focus is the home show,” cellist Nelson said. “We make the Salt Lake show special.”

That could mean some surprise guests, Schmidt said, though The Piano Guys typically don’t rely heavily on guests. “Guys” is the operative word in the group’s name (which was taken from Anderson’s St. George piano shop). Producer/videographer Anderson and music producer/songwriter van der Beek are as instrumental as the frontmen, and they often join in on percussion and vocals.

“Bands have two options: become a brotherhood or break up,” Nelson said, adding he’s grateful The Piano Guys are on the “brotherhood” path.

“There’s a lot of variety in our music, and there’s a lot of variety in our personalities,” van der Beek said. “We’re all so different.”

“Al and I share a lot of ‘yellow,’” Nelson said, referring to the color-based personality classification system in which “yellow” personalities are motivated by fun. “Jon is the kind ‘white.’ Paul flipflops between ‘red’ and confused.”

“I’m the logical, grounded one of the group,” Anderson corrected.

(Francisco Kjolseth | The Salt Lake Tribune) Pianist Jon Schmidt, left, and cellist Steven Sharp Nelson, two of the four that make up the American musical group The Piano Guys, joke around with one another while talking about how they first met during a visit to their home studio in Sandy recently.

The web of friendships and professional connections that gave rise to The Piano Guys is a little tricky to untangle. Anderson met Schmidt when the pianist stopped in at his shop on the way to a Tuacahn Amphitheatre gig, Schmidt met Nelson when they both played backup to folk-rock musician Peter Brienholt, and Nelson met van der Beek when the latter helped him move in down the street from van der Beek’s home. Once all the pieces came together, they started making those click-grabbing YouTube videos, which have taken them and their piano to locations such as the Great Wall of China, the ancient city of Petra in Jordan and the Christ the Redeemer statue in Brazil.

“We had a deep desire to make spiritual music — not exclusively religious, but uplifting … with the ability to brighten someone’s day,” Nelson said, explaining why he and van der Beek first hit it off.

At first, the group recorded late at night in van der Beek’s basement studio, “in the nooks and crannies of our discretionary time,” said Nelson, who was working in real estate at the time.

After a while, van der Beek “finally heard this voice saying, ‘Idiot, you can’t keep doing this to your family.’” His wife never complained about the disruptions, “but when I told her, ’We’re moving and we’re not taking the studio,’ it was the best thing I’ve done,” he said. The four men now own that house jointly; Anderson stays there when he drives up from St. George.

Their time together is marked by virtually nonstop (albeit good-natured) humor, but “we have lots of really serious moments,” Nelson said. “If we were flippant all the time, we’d have no substance. … One thing we take seriously is composition. We dig for the meaning and the right feeling. And we’re not flippant about our roles as fathers and husbands.”

Still, he said, “Humor is such a great antidote for entitlement.”

“Christmas Together,” the group’s seventh album, boasts appearances from Spanish supertenor Plácido Domingo (“that’s the advantage of being with the same record label [Sony Music Masterworks],” Nelson quipped), British sextet the King’s Singers, the Cathedral Choristers from New York City’s St. John the Divine, in addition to local favorites such as David Archuleta, Lexi Walker and the Mormon Tabernacle Choir.

The closing track, “The Sweetest Gift,” is dedicated to Schmidt’s daughter Annie, who died in a hiking accident last November at age 21. Schmidt came across a live recording of the song on Facebook, posted by Ohio singer-songwriter Craig Aven, and “felt that as many people needed to see this song as possible, and I wanted to see if I could play a role,” he said. Aven sings his song on the album.

Sharing his personal tragedy with the world “is something that couldn’t be avoided,” Schmidt said, recalling the national press coverage of the search for his daughter in the Oregon mountains. “We didn’t choose that. But we’re trying to do the best we can with that. … The feedback we’re getting is that that song is making a difference. It’s beneficial to people. So many people have lost someone close to them — more people than not. They can relate.”

Van der Beek said ”Christmas Together” is the album of which he’s most proud. “It encapsulates our core beliefs without being in your face,” he said. “For us, what Christmas means is Jesus Christ. Every song [on the album] speaks of that.”