The Piano Guys have more than 3 million YouTube subscribers. But for one married couple from New Jersey, the relationship with the popular musicians goes beyond mere fandom.

Bob, 54, and Joanna Walch, 57, from Cinnaminson, New Jersey, were baptized into The Church of Jesus Christ of Latter-day Saints last year, and their conversion began with a fascination with the music of the Piano Guys.

Pianist Jon Schmidt knows it would be presumptuous and untrue for the Piano Guys to take credit for the Walches' conversion. After all, he said, they pray before every show that "this whole thing can be not about us, but about having an impact on someone else for good."

In a way, the Walches are the answer to their prayers.

In the summer of 2013, the Walches' nephew had rushed into their room to show them a video of the Piano Guys performing "What Makes You Beautiful." In the video, all four band members — Schmidt, cellist Steven Sharp Nelson and producers Al van der Beek and Paul Anderson — hit and pluck the chords of an open piano, creating an acoustic/percussion rendition of One Direction's hit song.

Later that night, Joanna Walch watched the group's videos for hours, and she watched some more at work the next day. She eventually purchased tickets to a Piano Guys show in Albany, New York, a four-hour drive from the couple's home.

"They had so much love and energy, and no problem stating that they were Mormon and had 16 kids between the four of them," Joanna Walch said of their first meet-and-greet with the band before the show, a feature that came with their VIP passes.

During the show, members of the Piano Guys had said that it was not luck or fate that had brought the band together, but that God had brought them together and helped them touch others' lives through inspiring music.

"I was so fired up by the time that concert was over," Joanna Walch said.

The Piano Guys felt something special that day, too. Schmidt said in an interview that the Walches left a lasting impression on him after the meet-and-greet.

"It was kind of like they were people that we had known before," Schmidt said. "Something immediately clicked with them."

At home that evening, Joanna Walch purchased tickets to a second show taking place just nine days later. For another year, she and her husband emailed the Piano Guys and went to many more pre-show meet-and-greets. The question the couple always had for the musicians was, "Why are you so happy?"

Their response: the gospel of Jesus Christ.

Jeremy Crawford, operations manager for the band, recommended the Walches call missionaries of the LDS Church in their area through the church's website. But the Walches took it a step further and decided to meet the missionaries at a sacrament meeting.

The Walches were amazed at the friendliness of church members in their area, something that made their path toward membership easier. They immediately began taking the missionary discussions and shared their progress with the Piano Guys.

"We were the first ones they wanted to tell," Schmidt said. "These emails were just so fun to get. I would share them with my family."

However, the Walches' path toward becoming members of the church was not always easy. Bob Walch, a former Catholic, had been searching for a new faith for five years and wanted to be sure he was making the right decision.

Bob Walch said in an interview that, one week before his baptism, he began to wonder whether he was doing the right thing. That's when a package arrived for the couple in the mail. Inside were two sets of scriptures with their names embossed on the covers. And inside the scriptures were handwritten testimonies from Crawford and Schmidt. Written testimonies from the rest of the band members arrived just after their baptisms.

"That changed everything," Bob Walch said. "We're just two people, but they would tell us how they admire us and what we're doing."

The Walches were just as admired by their fellow ward members and by the missionaries who taught them. Brittany Daniels, 25, was one of the missionaries who taught the couple.

"They are some of the closest friends I made on my mission," Daniels said. "Bob has always been interested in family history — he was the one who was showing us how to use FamilySearch."

The Walches started going to the temple in December to do baptisms for their ancestors. They finished 15 names the first night, but that was just a drop in the bucket. Bob Walch's fascination with his family history has already resulted in him finding 800 family names that date as far back as 1422.

"We just felt like these people are going to make such a great impact and be able to strengthen so many people," Schmidt said, relating his first impression of the couple. Now, he said, the Piano Guys see they couldn't have been more right.

In August, the Walches will be sealed together in the temple. The Piano Guys have already RSVP'd.

'What Makes You Beautiful' by the Piano Guys