Adam Levine thinks Joe Jonas is a "beautiful man".

Adam Levine

Adam Levine

The Maroon 5 frontman recruited the DNCE singer to help him mentor the hopefuls on his team during the upcoming season of US singing competition 'The Voice', and has joked that his reason for choosing Joe, 27, was "purely shallow".

He teased: "It was purely shallow. He's a beautiful man."

Really though, Adam, 38, is pleased with his decision to get the former Jonas Brother to assist him, as the hunk offers "very sound advice" to the contestants.

Adam added: "He's very mellow, which is good, because it kind of balances me out. He offers good advice, and very sound advice. I trust his opinion, because I'm a fan of him. Whenever you can trust that someone's going to help out these kids, that's what you want in a mentor to help you. And trust me, I've worked with people I didn't necessarily know as well, and it hasn't been as good, because you have to have kind of chemistry.

"I think because we get along, and we're definitely very like-minded in a lot of ways, it makes it easier for us to coach together."

And for Joe, his experience on the show has been "great" so far, and he's "very impressed" with the caliber of talent he's seen.

He said: "It's been great! I think this is spoiling me, because everyone we've been able to work with is really talented and I'm very impressed with, I guess, Adam's likes, and listens and, obviously, what he's attracted to, when it comes to singers. So, I've had a pretty easy job being able to listen to some great, talented people."

The 'Cake By The Ocean' singer hasn't even had to give out much criticism.

He told 'Entertainment Tonight': "We've been pretty lucky. But the small creative criticism we've been able to give, I think, like, you can think that it's probably something they are familiar with already, or something they already know, but when you just bring it up, it's surprising how that little advice can go a long way."