"It solidified what we do for a living to our parents in a certain way," Hearst said. "Now that we're full-grown adults, our parents can relax in their easy chairs knowing that we managed to weasel our way onto Letterman, so it's probably going to work out."
They met on the music scene as both pursued separate careers, Trent in a rock band and Hearst as a country singer. They would perform locally as a duo for extra money during breaks in their "real" careers.
Marrying their music careers was harder than getting married in real life, Trent said.
"Neither of us knew if it was really going to work," Hearst agreed. "We figured it's better to give it a shot and be on the road together than be relegated to a long-distance marriage. Our worst nightmare was that we would both be really successful (separately)."
There are ego issues to deal with in creating a duo: Who is going to be the lead singer? They both are, really, sometime switching between lead and harmony in the same song.
Now they have a hard time singing apart, Hearst said. They released "O' Be Joyful" in July.
Besides their own shows, Shovels & Rope have toured as opening acts to artists like Justin Townes Earle, Jason Isbell, the Felice Brothers, Hayes Carll and Butch Walker.
Carll loves Hearst's "huge" voice and personality and asked her to sing a duet with him on one of his discs. He invited them on the road, saying "it was exactly what I wanted to see if I was going out to watch a show.
"My audience loved them," he said. "They just tore down the house every night. It was so much fun to go out and watch people 'discover' them every night. I had one of my best friends who's known me for years say, 'You know how I know you're doing well? That band is opening for you.'"
A sense of living on the edge musically as a duo is part of what makes audience members root for Shovels & Rope. "We are inspired by limiting ourselves to what the two of us can handle with our four arms, four legs and two heads," Trent said.
Neither knew how to play the drums before a friend gave them a kick drum he had found in the garbage. Hearst shudders at the memory of recently trying the piano onstage for the first time during a cover of Bruce Springsteen's "Johnny 99." "I bombed," she said.
A friend may come onstage to play a trumpet now and then, and other musicians will contribute to recordings, but the couple said Shovels & Rope will stay as a family band.
"It wouldn't be as good if it were more rehearsed," Trent said. "It wouldn't be as good if it were better."
With that, his wife laughed in the background.