Monday night's broadcast featured a round of epic solo performances, along with the judges critiquing each performance. Even Idol host Ryan Seacrest admitted the talent gave him chills and blew him away.
Katy loved Shawn's vocals but asked him not to forget his lower register, which brings a thick, rich and smooth sound.
Laine Hardy, an 18-year-old musician from Livingston, LA, sang "Bring It On Home To Me" by Sam Cooke.
The judges gave Laine a standing ovation and Lionel pointed out, "We are in trouble now because, ladies and gentlemen, Laine has discovered a new thing. You can take that look all the way to the bank."
Katy admitted she was scared of Laine, which was a good thing, because he commanded the stage. Katy wasn't sure how she was going to let anyone go.
Luke was happy by how far Laine's voice has come since last year.
"What I'm even more excited about is everything you're doing currently looks like you are trying to win this whole competition," Luke shared.
Uche, a 24-year-old wedding singer from Sugar Land, TX, took the stage with "Figures" by Jessie Reyez.
Katy was so taken by Uche's performance that she fell on the floor and could barely stand when Lionel and Luke were also on their feet.
Lionel said just when he thought he was prepared for Uche, he brought his performance to a whole other level.
Katy told Uche to keep finessing his vocals and moves, and then Luke expressed how the judges had almost sent him away -- which would have been "a cataclysmic mistake."
Katy agreed the judges almost eliminated him because he's "a lot," but now she believes that's okay.
"[People] want big and they want to be moved, but you just have to make sure you take them on that journey," Katy told Uche.
Eddie Island, a 25-year-old rideshare driver from Nashville, TN, sang "Ho Hey" by The Lumineers and nearly made Katy cry.
The judges gave Eddie a standing ovation as well, and Lionel could tell Eddie is taking this competition seriously.
Katy appreciated Eddie's sense of humor but said he's a musician first and then a comedian. Katy noted he has "all of it."
"You can't teach personality and authenticity and originality," Luke explained, adding that a singer may be great but also boring and that's not good.
Evelyn Cormier, a 19-year-old teacher from Claremont, NH, performed "Leaving On a Jet Plane" by John Denver for her Top 20 solo.
Katy said Evelyn has one of the most unique voices she's ever heard and is "so special" and authentic.
Luke had trouble figuring Evelyn out at the beginning of the competition but now he can sit back and just say, "Wow, this is amazing."
Luke became a fan, and Lionel told Evelyn, "Anyone can be a singer. Careers are built on being a stylist. It's about your style. Hold onto that and I'll see you at the top."
Alyssa Raghu, a 16-year-old high school student from Orlando, FL -- who made the Top 24 last year but then got cut -- sang "Ain't It Fun" by Paramore.
Luke wasn't sure the song choice was perfect for her, but he at least enjoyed watching her have fun on the stage. He said she's upward and onward.
Lionel thought the second half of her song was better than the first and she should stop thinking about her vocals while performing.
Katy saw Alyssa maturing before her eyes and growing into a confident woman. Katy, however, wanted to hear more of Alyssa's range.
Ryan Hammond, a 25-year-old medication technician from Modesto, CA, performed "You Say" by Lauren Daigle.
Lionel was captivated by Ryan's storytelling ability but asked the contestant to "own the stage."
Luke agreed Ryan can elevate a room with just the power of his voice, but Katy added he should try to pull the audience in more.
Raquel Trinidad, a 21-year-old server from Tampa, FL, took the stage with "Lovefool" by The Cardigans.
Katy could see Raquel was becoming an artist right before their eyes. While it wasn't a performance that blew the judges away, Raquel proved whom she'd like to be as an artist.
Luke admitted he struggled to connect to Raquel and the lyrics but her performance came alive for him halfway through the song.
"Don't abandon this. Don't try to be anything you're not. We know who you are. The crowd is going to love you for you regardless of the show... That personality and quirky thing you've got, keep it forever because it's your signature," Lionel explained.
Logan Johnson, a 20-year-old golf shop attendant from Boise, ID, took the stage with "Love Don't Live Here Anymore" by City and Colour.
Logan was smooth and sultry, but Luke confessed the song started "a little sleepy" for him. However, Logan looked like "a seasoned veteran" onstage.
Lionel said Logan's "sleepy" is his "sexy" and so he should just bump up sexy a bit. Lionel felt Logan was heading in the right direction.
As for Katy, she thought Logan presented the judges "a rehearsal," as if he marked through the song for half of it. Logan shined, however, towards the end.
Katy told him not to be afraid of taking chances but to remember his strongsuits.
Dimitrius Graham, a 27-year-old retail associate from Baltimore, MD, performed "Hello" by Adele.
"Every time you open your mouth, we find somebody else inside. I heard some notes tonight I have never heard come out of your mouth before. That is the way you're supposed to do this show," Lionel said.
Katy agreed she was holding onto her seat when Dimitrius belted out some high notes, and Luke thought it was great Dimitrius was learning how and when to show restraint or subtlety in his performances.
Riley Thompson, a 16-year-old high school student from Mabank, TX, sang "Jolene" by Dolly Parton.
Katy thought Riley's performance was great but she wanted a little bit more "grit," especially considering what the lyrics were about.
Luke agreed Riley needed more angst in her performances and should push herself a little bit more.
Lionel knew Riley's growth would take time but she was showing guts and raw talent.
Walker Burroughs, a 20-year-old college student and resident assistant from Birmingham, AL, performed "How Deep Is Your Love" by the Bee Gees.
"You just blew me away, brother. To start with a cold open like that and be on key like that, you just look like a seasoned pro to me," Luke said.
Lionel said Walker will become even greater with more experience, and then Katy pointed out he was "like the guy next door" who has "blossomed."
Katy added Walker's song choice showed off his intelligence and beauty, and that it didn't hurt he was dressed like Harry Potter.
For her Top 20 solo performance, Bumbly, a 27-year-old subway singer from New York, NY, belted out "Vision Of Love" by Mariah Carey.
Lionel could tell Bumbly's nerves took over a bit and so she should just relax and sing because she's "got the goods."
Katy didn't think the song was a good choice for Bumbly because her package is about the personality and texture in her voice.
"It's fun, and I feel I lost a little of that in that song choice," Katy told Bumbly. "But with that being said, I just love you."
Luke admitted the judges were just picking her apart because she has an unbelievable voice and they'd just like to see her be a bit more free with her vocals.
Ashley Hess, a 27-year-old dental hygienist from Fremont, CA, took the stage with "Dreaming With a Broken Heart" by John Mayer on the piano.
Katy thought she was at Ashley's show and found herself lost in the performance. Katy, however, told Ashley not to forget the audience is there because it'd be great to interact with them a little more.
Luke said Ashley often digs into this sultry, soul part of her voice that is "world class" and "iconic" in a way.
Lionel agreed, saying, "The world is solid. That was about as solid of a performance as I can tell you."
Alejandro Aranda, a 24-year-old dishwasher from Pomona, CA, sang "I Fall Apart" by Post Malone for his Top 20 performance.
"I am not worthy to critique you," Luke confessed. "I don't know if this show -- in the history of the whole show -- has ever had somebody like you, in my opinion."
Lionel said he was "overwhelmed" by where Alejandro could possibly end up.
"You're so much cooler than us," Katy said, adding that his arrangement was "so next level" and she was just thrilled to watch his show.
Kate Barnette, a 23-year-old nanny from Kennesaw, GA, performed "Sunday Morning" by Maroon 5 for her Top 20 solo.
"That was dope! That checked so many boxes," Katy yelled.
"You came and you got involved and connected, and it was all just so natural! Honestly, I didn't really get who you were until just a few episodes again, but now, it's like what?! Who is this girl?!"
Katy added Kate is a "well-oiled machine," and Luke noted she has developed a style that's all her own and it's so impressive.
After Luke admitted he was "anxious" about having to make some cuts, Lionel complimented Kate's "funk."
"You are giving it to the rest of the contestants. I'm loving you. Congratulations," Lionel said.
Jeremiah Lloyd Harmon, a 26-year-old music teacher from Catonsville, MD, performed "Make You Feel My Love" by Bob Dylan on the piano.
The judges gave Jeremiah a standing ovation. Lionel said he was "sucked in" to Jeremiah's story at the very first note.
"That was a brilliant performance. Brilliant," Lionel noted.
Katy was beyond moved to watch an "incredible" and serious" musician on that stage.
"You are a very important contribution from the universe to music, and you should never forget that -- whatever happens," Katy insisted.
Luke joked about how he needed to go home and practice after watching Jeremiah perform.
Laci Kaye Booth, a 23-year-old college student from Livingston, TX, was up next, and she sweetly sang a slow and stripped-down rendition of "I Want You To Want Me" by Cheap Trick.
The judging panel gave Laci Kaye a standing ovation as well.
"You just showed us a whole other level of confidence," Katy said.
"I mean, you were for sure an A+ before in my books, but now you are just ungradeable. It's really, really good."
Luke said she "knocked it out of the park," and Lionel noted she has found herself in the group of "ridiculous talent."
Wade Cota, a 27-year-old musician from Phoenix, AZ, then closed out of the show with "All I Want" by Kodaline.
Wade got all three judges on their feet.
"This will sound cliche: A star was born," Luke gushed.
Lionel insisted the music business needs to be inspired, telling Wade, "Somebody has to come and shake the world up, and that voice you have, I know that's you, my friend."
Katy said she felt grateful the judges could help to nurture, grow and support Wade.
"We may have found you, but tonight, you found you," Katy noted in tears.
Next week, American Idol will feature two nights of all-star duets in which the Top 20 will be paired up with famous singers and perform with them.
After the duets round, the Top 14 finalists will be determined and those singers will eventually compete for home viewer votes.