The CMA Fest is known for its powerhouse performances and surprise on-stage collaborations, but even that crowd wasn't ready for when Lil Nas X and Keith Urban surprised Billy Ray Cyrus on stage to rock out together to the smash-hit of the summer, "Old Town Road."

Shortly after the show-stopping jam session, Cyrus told "Good Morning America" that this performance was special to him.

"It's just a massive amount of people singing the same song and feeling it and it's a unique feeling," he said. "I never thought I'd ever get to feel it again. And I mean it's just been really special."

Lil Nas X added that this was his "favorite performance so far."

"You know, I was feeling it. Like the audience, Keith, Billy, you know everything just came together. It was great," he said.

Cyrus called Lil Nas X "a very humble man" despite skyrocketing to fame almost overnight with his rap-country crossover hit.

"Everywhere I go, like, where people used to holler where's Miley," he said, adding that now, "everybody's going crazy ... 'Where's Lil Nas, where is Lil Nas?'"

Lil Nas X said people often ask him about Cyrus, most recently when he visited a Nashville Waffle House and he says a fan asked if her blind child could speak to Cyrus on the phone.

"I was at a Waffle House like three days ago and like this woman you want to talk to her blind child on the phone," he said. "And I was just talking to him and he was like, 'Put Billy on the phone.'"

Cyrus quipped that he's not quite sure if he believes that story, but nonetheless said that it "makes me so happy."

"I don't know if that's a true story or not, but I love it when you tell it. Please tell it everywhere we go," he said. "That's the funnest story that makes me so happy. But you know how happy you made that little boy."

"When I met this man I saw a light, he's a light in the world and that's ... I think what people see in him," Cyrus said of Lil Nas X.