The new American Idol judges -- Luke Bryan, Katy Perry and Lionel Richie -- appeared on Good Morning America on Wednesday morning (Oct. 4), and, naturally, the conversation briefly turned to Sunday night's (Oct. 1) shooting at the Route 91 Harvest Festival in Las Vegas, Nev. Bryan recalled speaking with Jason Aldean -- who was onstage when the shooting began -- early in the morning after the shooting, and how it affected him.

"Hearing one of your best friends shaken up like that, knowing they'll never be able to un-see these things, you get lumps, and you get nauseated," Bryan says. "It's hard -- I don't even know."

Both Richie and Bryan shared how, when artists are onstage, it's all about connecting with their fans. Richie says it's "terrifying" to think that moments like that -- and those fans -- could be in jeopardy.

Country Stars Respond Following Route 91 Harvest Festival Shooting

"As entertainers, you look at your fans -- you're not up there to do anything but connect with them," Bryan says. "I lay in bed, and when they show the faces of the victims -- they're our fans, they embody America. It's [a] country music festival, but it's America, and it's bigger than just -- it's just bigger than -- it goes so far beyond ..."

Perry, meanwhile, noted that she feels that now is the time to take "a good hard look at gun rerform, and the hands that these guns are being placed in."

"We have to put our foot down more than just sending our condolences," Perry says. "I know it's a touchy subject, but I think we really have to take a good hard look of it."

More than 50 people died and more than 500 people were injured during the Route 91 Harvest Festival shooting.

Remembering the Route 91 Harvest Festival Shooting Victims