Singers Josh Groban and Kelly Clarkson took to the stage accompanied by an orchestra and grand piano to sing a live duet of The Phantom of the Opera’s “All I Ask of You,” as part of Groban’s 2015 PBS special Stages.

The performance and television special came out as part of Josh Groban’s 2015 album by the same name, which debuted at number two on the Billboard 200 list, according to Billboard.

Groban’s Stages is a collection of Broadway musical numbers from well-known hits like The Wizard of Oz’s “Over the Rainbow” to classics like “Bring Him Home” from Les Misérables.

And in this special PBS live performance — a studio version also found its way onto the album — American Idol star Kelly Clarkson joined Groban to sing a grand rendition of “All I Ask of You” from one of the world’s most famous musicals, the ‘80s hit The Phantom of the Opera, which was adapted from a French novel of the same name.

Early on, Groban reached out to Clarkson in hopes that she would join him on the album. But according to an interview with Billboard, Groban said he thought the collaboration would be “a long shot” given that the American Idol star had a new baby and a new album at the time.

Despite the initial pessimism, however, Groban decided to contact Clarkson anyway. And as a huge fan of hers, Groban is glad he did because Clarkson was enthusiastic from the start.

“I’ve been a fan of hers for awhile,” Groban told Billboard. “I just have always felt like her voice could do it all, and she certainly has proven that she likes to take risks. I was excited by her excitement; she loved theater and loved that song and wanted to take a crack at it.”

Groban said that the very same night he contacted her, Clarkson immediately sent back an iPhone demo of her singing the piece and asked for Groban’s opinion, according to Billboard. Suffice it to say that Groban was impressed.

“I thought, ‘Oh my God, people are gonna be shocked when they hear you really open up on this,’ because she can do it,” he told Billboard.

Shrouded in fog with crystal chandeliers overhead, the musical duo walked on stage in 2015 and gave the challenging musical number their best shot in front of a huge crowd in the PBS special performance.

And it seems they delivered. After the two had finished their elegant vocal dance, the audience gave a standing ovation, and a pleased Groban gave Clarkson a hug. Groban attributed at least part of the duet’s appeal to the musical duo’s unique, unexpected interpretation of the classic song.

“Whenever you can take a classic song that everybody knows and add a nice surprise to it, that’s always the best thing,” Groban told Billboard. “You give people what they weren’t expecting. So I think Kelly and I singing this song is one of those.”