"We started harmonizing together on the job," Aaron Grey tells PEOPLE


For those who like a little Christmas spirit with their kitchen remodel, two festive friends in Indiana are more than happy to keep up a steady harmony as they hang drywall and install baseboards.

On a whim five years ago, Josh Arnett and Aaron Gray started singing on the job to pass the time, wowing clients with their a cappella renditions of “How Great Thou Art” and “Amazing Grace.” Now the pair has become an Internet sensation as The Singing Contractors, with more than 40 million Facebook hits and two popular CDs of spiritual favorites.

Friends since age 13, the two grew up singing in church, but didn’t start working together as building contractors until six years ago.

“We started harmonizing together on the job, and one day, I told Josh, ‘Just for the fun of it, let’s record ourselves and put it on Facebook,’ ” Aaron, 40, who lives in Lebanon, Indiana, and is a father of three, tells PEOPLE.

Adds Josh, a 41-year-old father of four from Fortville, “I was like, ‘Um, no.’ Of course, Aaron did it anyway. When it was first put out there, a few people didn’t like it and teased us, but those who did like it started calling us The Singing Contractors.

“We never had to name ourselves — it just happened. Now I’m glad Josh made the video, because it’s been so much fun.”

After the video of the two singing “Great Thou Art” went viral with 15 million Facebook hits in September, the pair decided to add some Christmas music to their remodeling repertoire. In just two weeks, “Mary Did You Know” has been viewed more than 23 million times on Facebook and 202,000 times on YouTube.

“It’s been overwhelming,” says Josh. “Our phones now ring constantly with people sending in song requests. Singing is a passion for both of us — it comes from our hearts.”

In their flannel work shirts and baseball caps, the duo is now often recognized when they run out to get a sandwich for lunch or buckets of paint to finish a remodel.

“We feel like what we’re doing is a ministry of sorts,” says Aaron, who grew up helping his dad with bricklaying and painting jobs. “We’ve heard stories of people being saved, getting off drugs and not committing suicide because they saw our videos. We’re just two simple guys spreading a message, so it’s an honor to know we’re making a difference.”

Adds Josh, “People tell us that what we’re doing has resonated in their lives. Sometimes, if you feel your life is spiraling out of control, you need to hear a message of love and peace.”

“This is our way of offering encouragement,” says the former steel factory worker.

Adrian and Happy Payne
Credit: Adrian and Happy Payne
Adrian and Happy Payne
Josh Arnett (left) and Aaron Gray
| Credit: Adrian and Happy Payne

With Josh handling lead vocals and Aaron chiming in with his rich tenor, The Singing Contractors can find the harmony of almost any ballad after Googling the lyrics. They claim to work in harmony, too.

“We have each other’s backs,” Josh tells PEOPLE. “Working together, there are times when we don’t agree on everything, but Aaron is always upfront and honest. He’s a true friend.”

Adds Aaron, “Where I tend to speak my mind very bluntly, Josh will aways take a kinder approach. Good friends are hard to find nowadays, but Josh is one who will always back me up. I admire him.”

He and Josh aren’t certain where their crooning will lead, but they do know one thing: Whether singing in the shower while installing tile or trilling while drilling, “the music has to speak to us,” says Aaron. “When we feel good inside, that’s when we know we’re on the right track.”