Jack Cassidy Returns to 'The Voice,' Belts Out Elton John After Being Selected as Alicia Keys' Comeback Artist

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Jack is back!

After his heartbreaking elimination in The Voice’s knockout round, Jack Cassidy has returned to the NBC singing competition after coach Alicia Keys brought him back.

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“I don’t want you to go home, so you’re going to be my comeback artist!” Keys said on Monday's show, surprising the nephew of acting icon David Cassidy and son of Patrick Cassidy.

"I brought Jack back because I know we haven't seen what I've seen,” Keys explained to cameras. “When I hear him sing, I hear something really unique."

During their coaching session, Cassidy admitted that there had been a “disconnection” between his private performances for Keys and his delivery in front of the show’s live audience.

"When I see you in this room, in our little private sanctuary, I'm witnessing you at about 97 percent,” Keys agreed. “Then, when we go out and it gets live, I might be witnessing you at about 70 percent. This time around, we have this incredible opportunity to show everybody 100 percent."

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Preparing to perform the Elton John classic, “Don't Let the Sun Go Down on Me," Cassidy noted how he learned most of the GRAMMY winner’s songs on the piano growing up.

"This is vocally the biggest song he has done and I want him to just deliver,” Keys said.

And deliver he did!

Nailing the song, Cassidy had audience members swaying their arms side-to-side and applauding, while Keys was proudly beaming with a giant smile.

"It's just such a blessing,” she said after his performance. “There's this greatness inside of us and sometimes it's so scary. Sometimes it's so hard to access and you don't know what to do with it. I saw that in you, and I see that in myself sometimes, so I'm rooting for you.”

“This is absolutely that 100 that I was talking about,” she continued. “You did it, and if nothing else, you rose to your greatness here tonight on that stage and that is the most important, incredible thing. And, I know your family is home going crazy for this performance.”

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Acknowledging his famous family, Cassidy shared how his grandma, Partridge Family star Shirley Jones, was the most excited about his journey on the show.

"My grandma's super pumped,” he said. “She's so honored that she gets to see the third generation take the stage."

See more on Cassidy’s experience on The Voice below.