We’re all familiar with R&B boy bands, teen dream boy bands and K-pop boy bands.

But what about a medieval boy band?

While taking a meditative stroll through the royal monastery of San Lorenzo de El Escorial in Spain in 1989, Frank Peterson listened to modern-day music on his Walkman. Inspiration hit as he took in the medieval monastery around him, and he wondered what would happen if he paired the two worlds of ancient Gregorian music and modern-day hits?

At the time, Peterson was a member of the German musical project Enigma, renowned for its New Age, electronic and ambient music. The group’s debut 1990 album, “MCMXC a.D.,” hit No. 1 in 41 countries.

Following that chart-topping sensation, Peterson went on to create Gregorian, a group of male singers who dress in monk robes and chant pop-rock songs, including those by Enigma. Their first album, “Masters of Chant,” dropped in 1999 and was followed by 20 more. Nowadays, their repertoire is up to about 300 songs, and includes classical, pop and rock tunes from the last four decades.

Gregorian will bring its Pure Chants World Tour to Pikes Peak Center on Tuesday.

“It’s really theater instead of just a show,” said dance captain Tristan Stocks. “It’s not just Gregorian chant. It’s more of a flavor of that sound world meeting with the sound world of really loved music and modern music.”

What to expect

Eight men who are mostly from the United Kingdom, minus the soprano, who’s from Romania. The accompanying band is from Germany, and there’s one female singer, Amelia Brightman, whose sister is the popular classical soprano Sarah Brightman. As a founding member of the group, Amelia does the occasional solo or duet with one of the men.

“It starts subtly, without instrumental music,” said choir leader Ashley Turnell. “It’s more about the choir and solos. But it gets ramped up with more rock numbers.”

Playlist examples

“The Sound of Silence” by Simon & Garfunkel; “Dancing in the Dark” by Bruce Springsteen; “Tears in Heaven” by Eric Clapton; “O Fortuna” from “Carmina Burana”; “Clocks” by Coldplay; Enigma.

“We do have some original music. A lot of tracks are really well loved and reimagined in a style that speaks differently to people,” Stocks said. “It has a really soulful element – something that connects.”

Who are the singers?

About 25 singers make up the Gregorian roster, though only some of them tour at a time. They’re all professional singers based in the U.K. who have experience working in smaller ensembles, session work and church work.

“All of the musicians come from different backgrounds,” Stocks said. “Some have an operatic background, or a theater or pop music background. Some of the band are classical, some rock, some metal. It’s a melting pot.”

Are they really monks?

No.

“I never know a good answer,” Stocks said. “Sometimes we say on stage (we are). But we’re not real monks, though we all have monk-like features.”

IF YOU GO

What: Gregorian: Pure Chants World Tour

When: 7:30 p.m. Tuesday

Where: Pikes Peak Center, 190 S. Cascade Ave.

Price: $46-$93; axs.com, pikespeakcenter.com