Brian McKnight will appear as a guest mentor during Sunday's episode of American Idol

Brian McKnight is bringing all the nostalgia to American Idol.

In a PEOPLE exclusive clip of Sunday's episode, the R&B singer, 51, performed his hit song "Back At One" with lucky contestant Alana Sherman — and judges Lionel Richie, Luke Bryan and Katy Perry were all for it.

At one point, Richie flashed the number three with his fingers, while Perry sang along.

American Idol
American Idol

"Great energy on your solo performance," Bryan, 44, tells Sherman after the performance. "Way to bring the energy. Even with Brian McKnight up there, especially towards the end, you really started coming into your own and hitting notes."

"I loved the stuff that you did in the end there," he adds. "That was really great. "

McKnight, who has earned 16 Grammy Award nominations throughout his career, will appear as a guest mentor during Sunday's episode.

American Idol
Credit: Eric McCandless/ABC

"Being on Idol as a mentor has been something that I have wanted to do for a very a long time and when the call came in, there was no way I would say no," Brian, who released his first-ever dance/club remix EP "Brian Mcknight Remixed" on Friday, said in a press release. "Ideally, I would love to be considered as a judge for some of these TV talent shows, so that I can share lots of my journey with the new generation of singers."

McKnight will join the likes of Jason Aldean, Brandon Boyd, Josh Groban, Jewel, Tori Kelly, Katharine McPhee, PJ Morton and Ryan Tedder during Idol's two-night All-Star duets episodes on Sunday and Monday.