Malaya Watson, 16, channeled her inner Aretha Franklin, belting a version of "Ain't No Way" that had Keith Urban on his feet.
"You had this voice right from day one, you just needed to be with it," Urban said. "You were with it tonight."
"You're blossoming into a star right in front of our eyes," said Jennifer Lopez. "You're gonna run away with this competition."
Alex Preston, 20, was a true original singing his original song, "Fairytales," which sounded as if it could be playing on radio stations right now.
"Half these guys were singing it with you," Urban noted, nodding at the other contestants. "That's a good sign."
Jessica Meuse, 23, sang "Blue Eyed Lie," an original song that showed off the "ferocity" of her voice, according to Urban.
"It reminded me of Cher from the '70s or Nancy Sinatra," said Harry Connick Jr., referring to the stillness of her body juxtaposed to the power of her vocal.
Rosy-cheeked teen Sam Woolf was pitch perfect singing "Lego House" the second time around, playing guitar on a pretty set filled with mismatched lamps.
"You're getting better every week," said Urban, while Connick believed the "wrong word" was being used to describe him.
"Connection not confidence … pick someone to look at, and smile at them … it will change your world," Connick advised.
Last week's standout Caleb Johnson, 22, also changed up Aretha, giving "Chain of Fools" a soulful, old-school rock sound that had Urban raving, "You are a blues warrior, you are a soul conqueror, you, Caleb, are a rock 'n' roll Viking," and Connick telling the rocker, "I would love if you did something that wasn't so loud once."
C.J. Harris, 23, sang "Soul Shine," and the song certainly showcased his inner light.
"There's something that comes from you that touches my heart," said Lopez.
"I can tell that you have been working … on pitch," said Connick. "If you get a record deal … and don't get your pitch down, they're going to auto-tune it, and suck the life out of you."
Dexter Roberts, 22, sang "One Mississippi" and showed Lopez "so many different nuances in your voice that I hadn't heard."
"You sat on that stool and sang the crap out of that song," said Connick, while Urban urged him to "pay less attention to the sound of your voice … think about the lyric."
Jena Irene, 17, retooled Adele's "Rolling in the Deep" into a sort of torch song that Urban "loved every second of."
The duets were largely forgettable (and occasionally uncomfortable), although Jessica and Caleb channeling Stevie Nicks and Tom Petty was the standout.
Results air Thursday (9 p.m. ET) on Fox.