They needn't have worried as they sounded fantastic on "Burnin' Up," "Year 3000," "When You Look Me In the Eyes" and "Lovebug." They even dropped into their latest track, "Sucker," and it was enough to get James Corden excited.
By the end of the ride, he was ready to throw away his purity ring, too. And yes, the brothers discussed their infamous purity rings, as well as what it was like working under the Disney regime early in their career. Plus, they got real about who broke up the band.
Just to make sure they were really really real, though, James Corden brought in his lie detector buddy to strap them in and put them to the ultimate test. And just as they did with "Spill Your Guts or Fill Your Guts," the boys proved more than willing to be truthful with one another, even if the answers might sting a little. Hey, they know there's love underneath.
Plus, all that therapy they went through before coming back together clearly helped them hear one another and set aside feelings of hurt for petty things. That's good advice for anyone.
According to Nick, the whole idea of bringing the band back together started with a different idea altogether. "About a year ago we started talking about making a documentary together, that was how it started, just to tell our story, childhood into our career together," he said. "And in that process we did some very necessary healing. Because when things ended it wasn't the best."
Part of that healing apparently involved a drinking game of truths and honesty where they could open up about what frustrations they had with one another and who they blamed for the tumultuous ending of the band. Turns out everyone is in agreement on that one.
"I broke the band up but I got them back together, too," Nick said.
Kevin explained that while working through their issues and contemplating this documentary project, they realized "there was a magic when we were all together that we would love to feel again." Their fans would totally agree.
For the most part, the guys did a great job of being honest with one another while strapped to James' lie detector test. They were tasked with answering tough questions like which brother gets on their nerves the most and even which of their wives is most annoying.
Probably the funniest moment came when James asked Nick if he was a better singer than his brothers. There was a very pregnant pause during which Kevin and Joe both broke out laughing. They absolutely knew what he thought about this question, but he still said, "No." Cue John, the test giver: "That's a lie."
Nick's neverending wedding to Priyanka Chopra also came up a couple times during this segment. First, Kevin was asked, "At any point when you were at Nick's wedding, did you ever think how much longer is this going to be?" He told the truth, answering affirmatively.
"Was there a point during your many weddings where you thought, 'I'm done with these weddings?" James then asked Nick. He also told the truth, responding, "Yes, it was when I looked at the bill!"
Speaking of wives, Corden also asked Joe if any of his brothers' significant others get on his nerves. He said no, but that was deemed a lie!
Throughout, though, the boys were very eloquent in their answers, which they revealed stems back to their days under the Disney empire. It came up after Joe teased Nick about his aversion to sharing any of his clothes and Nick shot back that Joe bristles under any sort of authority figure.
"This stems from Disney days and kind of being told what we can and cannot say," Nick conceded. He even admitted that he used to take pride in being able to answer difficult questions while totally staying on message with Disney even if it wasn't the most sincere response.
"I took pride in it until I watched those interviews back years later and thought, I sound like a robot," he said. "I'm so annoyed with myself."
"A politician at age 13," Joe said. And both Nick and Joe absolutely proved it by again parroting nonsense answers filled with positivity and empty platitudes. Once the Disney machine embeds itself inside you, it never lets you go completely.
Of course, the most infamous angle about the Jonas Brothers that even goes beyond their fan base and into people who've probably never heard a single one of their songs is those pesky purity rings. Apparently, the brothers never even wanted to talk about them, as it was just something they did within their church.
But they were also incredibly public figures and suddenly wearing very physical and visible rings on their fingers. "everyone's like, are they married already? What's going on here?" Joe said.
As he explained it, they were kind of pressured into exposing the meaning behind the rings. "We were in an interview one day, the guy asked about them, we were like, we don't want to talk about them, and he's like, 'Well I'm just gonna say you're in a cult,'" Joe recalled.
"And we're scared to death, this is one of our first interviews, so we're like, fine, we'll talk about it."
Eventually, though, the boys got rid of their rings -- with Kevin hilariously admitting he became impure first, but don't worry there was no ceremony to mark this occasion -- got out from under the Disney umbrella and forged their own path.
And as exciting as it is to see the Jonas Brothers back together as a band, it's perhaps even more heartwarming to hear that they've come back together as brothers, too. Okay, for the die-hard fans it's more about the band and the chance to see them perform again. But family is nice, too.
They didn't have to wait too long, either, as the Jonas Brothers performed "Sucker" for the first time on television just a few moments later in the show. You can check out that performance below: