'American Idol' royal surprise: King Charles III visits with Katy Perry, Lionel Richie

HOLLYWOOD -- "American Idol" welcomed two very special guests for this week's episode.

We knew Katy Perry and Lionel Richie traveled across the pond to attend King Charles III's coronation. Little did we know Richie would convince the newly-crowned monarch to make an appearance on the reality competition show!

"He made it happen and it was of kind of a surprise for me today," said Executive Producer Megan Wolflick. "I've been on the show for 20 years and never had I had a day as wacky as today."

Host Ryan Seacrest agreed.

"This was the most globally bizarre thing that I've ever seen and the fact that, like, Lionel and Katy were borrowing some room in Windsor Castle until the wee hours of the morning, good for them!"

With Perry and Richie gone, Luke Bryan was left with two empty seats on the judges' panel.

The show recruited Alanis Morissette and Ed Sheeran to step in and complete the judging panel.

Before we learned which singers America voted into their Top 5, we heard from the season's Top 8: Colin Stough, Haven Madison, Iam Tongi, Megan Danielle, Oliver Steele, Warren Peay, Wé Ani and Zachariah Smith.

They each performed twice.

First, covering a song from Morissette's iconic songbook. Then, the eight finalists were paired up for duets of hits from Sheeran's catalogue.

When the votes were tallied, Haven Madison, Warren Peay, and Oliver Steele were all eliminated.

All three contestants said this was a once-in-a-lifetime, learning experience.

"The friendships, the exposure, I mean, everything about this has only been positive," said Madison.

Peay agreed.

"It's so cool to be a part of this thing and just the relationships we've made, the opportunities in front of us ... now the real work begins."

"How many other people are going to get to experience something like this in their life?" said Steele. "I think it's just absolutely incredible."

For the singers going home, this is just the beginning for what's next.

"I'm really to start playing some more shows, keep writing music, looking to maybe get some stuff released here soon and y'all will see me around," said Peay.

For Steele, a little piece of home will be nice, too.

"I've got more music to share with people. I've got friends at home that are waiting on me to work with them that I miss dearly. So I'm just excited to keep moving forward," said Steele.

Meanwhile, Madison is hitting the ground running.

"I've got a studio in my home so I'm going to release a lot of music. I'm going to be all over social media, looking at tours. I want to take on the world!" said Madison.

Next week is Disney Night!

The Top 5 will be mentored by singer and actress Sofia Carson while they take a trip to the happiest place on Earth.

Disney is the parent company of this ABC station.