FARGO — In its 21 seasons,

“American Idol”

has lived up to its name, producing stars like Carrie Underwood, Kelly Clarkson, Jennifer Hudson, Adam Lambert, Chris Daughtry, Fantasia Barrino and more.

Still, no year could match the down-to-the-wire competition of the second season in 2003, which saw

Ruben Studdard

squeak out a victory over

Clay Aiken.

That finale episode is still the single most-watched in the show’s history, attracting 38.1 million viewers, the biggest audiences for a regularly scheduled, live, non-sporting event in the 21st Century.

The singers hit the road last year celebrating the 20th anniversary of the show that made them household names. They’ll bring the tour to the Fargo Theatre on Thursday night, Jan. 4.

The concert includes songs the singers performed on “American Idol,” like “Superstar,” “Open Arms” and “Don’t Let the Sun Go Down on Me,” as well as a medley inspired by “Idol” mentors, like Gladys Knight, Smokey Robinson and Olivia Newton-John.

“There are songs we sang on ‘Idol’ and songs from ‘Idol’ that inspired us,” Studdard explains from his home in Alabama. “We want to give people that Ruben and Clay experience.”

While Studdrad has performed regularly over the last 20 years, Aiken spent much of the last decade unsuccessfully running for Congress in his home state of North Carolina. The tour marks Aiken’s return to the road for the first time since 2012.

“The only thing that’s changed in 20 years is that we’re older and now we have families,” Studdard says. “We just enjoy getting to do a job we love.”

Both singers were 24 when they were on “American Idol.” While Studdard studied music in college and had decided to focus on a career as a singer, he was not prepared for what an experience like “American Idol” could mean.

“I was really excited about the prospects, but didn’t know what to expect because I didn’t watch the first season. Every week was a new experience and opportunity,” he says.

A big part of that experience was performing before judges Simon Cowell, Paula Abdul and Randy Jackson. By the second season, Cowell’s sometimes sharp criticism was almost as well known as the performances, but Studdard felt his opinions were in line.

“Listen, Simon was par for the course,” the singer says. “I was a music major and his critiques weren’t any different from voice teachers I had in school. You need that. The music industry is a lot tougher than Simon is on ‘Idol’ because they go over everything to make sure they’re getting a return on investment.”

While the judging created some tension in the episodes, Studdard says there was little drama behind the scenes. The performers lived together in a mansion and got along, making for a cohesive environment.

“The way we were in that house was all like a family because 75% of us were from the South,” he says. “It was hard to foster a spirit of competition until we were on the stage and even then it wasn’t really a competition with each other.”

In a November interview in The Washington Post about the tour, Aiken said the camaraderie was genuine among that season’s contestants.

“I think one of the reasons we became not only friends with each other, but friends with everyone in our group, is because we had no idea what we were getting into,” Aiken said. “In subsequent seasons, I happen to know for a fact … the winner and runner-up had not spoken since their season ended. And we were both like, ‘What?’”

In that interview, Aiken also revealed that a staffer on that season of the show was his first boyfriend.

Studdard emerged victorious in the final episode, winning by 134,000 votes out of 24 million votes, a relatively slim margin that prompted some outrage from Aiken fans. Claymates, as they are known, may have felt vindicated when the singer’s first single, “This is the Night,” topped Studdard’s “Flying Without Wings” on the Billboard Hot 100 chart and became the best-selling single of 2003. Studdard didn’t mind. He released his full-length debut, “Soulful,” later that year and his version of “Superstar” was nominated for a Grammy. That honor put him in competition with his idol, Luther Vandross, who won the Best Male R&B Vocal Performance award for “Dance with My Father.”

“It was an adjustment going from obscurity to everyone knowing who you were,” Studdard says about the attention he received following his “Idol” win.

The singer has kept busy recording and touring and in 2018 released a very personal album, a tribute to Vandross who died in 2005. He’s been able to feature a couple of those songs in his tour with Aiken.

“He was my mother’s favorite artist so I grew up around his music and I became a fan. To have people compare me to him is a blessing,” Studdard says, adding that he’s excited to see the new documentary on Vandross.

What: Ruben Studard & Clay Aiken

When: 8 p.m. Thursday, Jan. 4

Where: Fargo Theatre

Info: Tickets from $49.50 to $69.50