On Thursday night's episode, former "Idol" contestants teamed up with current contenders to perform for the judges, and one of them was lucky enough to sing Nick's own single with him.
Nick was paired with Thomas Stringfellow, a 17-year-old high school student from Bentonville, Arkansas, and then Gianna, a
First up was Thomas.
"My first impression seeing him was that he definitely was a little nervous, bit of a deer in the headlights at first," Nick said of the young singer, but he also was there to help him along.
While Nick was of course familiar with the powerful chords, Thomas wasn't quite as enthusiastic about the song choice.
"This song is definitely out of my wheelhouse," Thomas said.
So Nick offered up some advice to help his trainee out.
"You know what helped me a lot? Was just singing in front of the mirror. Sometimes you have some habits that you don't even realize you do 'til you kind of see them or watch them on film."
Then the pair moved on to talk about girls, a topic they could both relate to. Thomas told Nick how he was down because his girlfriend broke up with him before he hopped on a plane for "American Idol," and Nick was right there with him. He and his girlfriend broke up around the same time last year!
"Use it for motivation, use it to connect to certain songs," Nick advised. "And, you'll be on national TV, she'll be sitting back home like 'what did i do?'"
The performance had a lot of energy and Nick killed it--the judges said so!--but Thomas was right that it wasn't a good song for him..
"It didn't feel quite right for you," Jennifer Lopez said after the performance. "It felt very Nick, it didn't feel very Thomas."
However, the judges concurred that his performance Wednesday night singing "Creep" by Radiohead was powerful enough to make up for his missteps with "Man in the Mirror."
Nick later tweeted how he had a blast returning to his roots.
Next up was Gianna, and boy was she lucky--she got to sing "Beautiful Life" with Nick!
"I've never sung this song as a duet, so it's going to be pretty cool," Nick said. "I've song it a thousand times, so hearing it a completely different way is pretty cool."
"When I first met Nick in person I was trying to like keep calm and collected and professional, but on the inside I was that teenager that's fan-girling all over Nick Fradiani and was like 'he's so cute,'" she said with enthusiasm.
And surprisingly, the 15-year-old and 30-year-old had more in common than you'd think. They both showed up to practice in leather pants!
"When you're twinning you're winning," Gianna exclaimed, and she ended up being right. Jennifer Lopez agreed that the two had more in common than you'd think at first sight.
"That was a nice song for the two of you to sing togheter. It's funny because you're so young, and he's grown, so to find something that the two of you can sing together and really enjoy, and the audience can enjoy...it was the perfect song," J. Lo said.
When Keith Urban asked Gianna what it was like to have Nick mentor her, she said, "It was amazing. I couldn't hit some of those notes that I thought I could hit, and then he was like, 'I know you can hit that note, you better hit that note.' And I hit it and I was like 'hayyy!'"
Before the big performance, after working out the kinks, Nick told Gianna how impressed he was with her.
"Thank you for singing my song so well," he said. What better praise is there than a song's artist saying you got it just right?
As for his advice to Gianna, while they didn't talk about girlfriends and breakups, they did talk about singing.
"When I stopped treating it like a crazy competition and was just like 'I should just have fun, because that's all music's ever been to me,' it makes it a lot easier," Nick said.
And it seems his mentoring paid off! Both Thomas and Gianna made it into the top 14.
Other past Idols to appear on Thursday night's episode include Reuben Studdard, Scotty McCreery, Fantasia, Caleb Johnson and Lauren Alaina.