The Piano Guys learned a lesson in 2020: Be careful what you wish for.

“True story: In 2019, we told our booking agent we wanted to take a year off touring in 2020 to focus on music production,” Jon Schmidt, pianist/songwriter of the Utah-based instrumental quartet, said this week in an email interview.

The COVID-19 pandemic took care of that, though Schmidt said, “now we are ready to get out touring again, so hurry up, vaccine!”

The quartet — which started in St. George with Schmidt joining forces with cellist/songwriter Steven Sharp Nelson, producer/videographer Paul Anderson and music producer/songwriter Al van der Beek — is marking 10 years together with the group’s 10th album, called “10.” It arrives in stores, physical and online, on Friday.

The album contains two discs, one of new material and one with the group’s greatest hits.

Singles off the first disc include “You Say,” which melds the melody of Lauren Daigle’s empowerment ballad with Ludwig van Beethoven’s “Pathetique Sonata,” and “Für Elise Jam,” a jazz-inflected take on another Beethoven classic.

There’s also a mashup of Boston’s “More Than a Feeling” and “Long Time,” and covers of Selena Gomez’s “Lose You to Love Me,” Ed Sheeran’s “Thinking Out Loud” and Lewis Capaldi’s “Someone You Loved.” Bonus tracks include a cover of Rascal Flatts’ “Bless the Broken Road,” and “Better Days,” an original song written by van der Beek, who also provides the vocals — a Piano Guys rarity.

The second disc features some of the Piano Guys’ most famous mixtures of pop and classical: “Let It Go,” which adds Vivaldi to the hit from “Frozen”; “Begin Again,” which augments the Taylor Swift song with Johann Sebastian Bach; and “Fight Song / Amazing Grace,” which combines Rachel Platten’s anthemic pop hit and the beloved hymn.

Also included is the song that got The Piano Guys on “The Tonight Show”: Their version of One Direction’s “What Makes You Beautiful,” with Schmidt, Nelson and other performers around a piano, playing the keys, banging the wood and plucking and bowing the strings.

The trick to mixing classical and pop, van der Beek said, is to remember that “the root of all music is classical music.”

Classical, Nelson said, “is such a significant part of who we are, and inherently and organically makes its ways into every one of our arrangements, whether stylistically or even, at times, melodically.”

Nelson and Schmidt, van der Beek said, “have a gift for finding some of the coolest classical melodies, and I’m always amazed when they show me how they work so well with whatever pop song we may covering at the time.”

The group’s viral videos — the most popular, a cover of Christina Perri’s “Twilight” love theme, “A Thousand Years” — have taken the group all over the world.

Bryce Canyon National Park was the backdrop for “Titanium / Parave,” which combined David Guetta’s pop song with composer Gabriel Fauré's work. They played “Somewhere Over the Rainbow” on a Hawaiian beach — with Nelson emulating Israel Kamakawiwoʻole’s famous ukulele cover on his cello, while Schmidt played the Shaker folk song “Simple Gifts” on piano. They did a version of the “Kung Fu Panda” theme, intercut with some Vivaldi, on the Great Wall of China.

“We’d take pianos and cellos and put them in places you’d never expect, like a speeding train, jumping out of planes, and even filming in four of the Seven Wonders of the World,” Anderson said.

Today, Anderson said, “it’s so much harder to capture people’s attention for five seconds, let alone a 3-minute music video, but we enjoy trying new things and will continue to do so and have fun in the meantime.”

After months without touring because of COVID-19, Anderson said, “it feels like the possibilities are endless. From what we can see, something great usually comes from our biggest trials.”