Sonenclar, 13, is partnered with LeAnn Rimes; Stevens, 37, will shared the stage with the group Little Big Town; and Fifth Harmony will pair up with judge Demi Lovato as anticipation builds for a winner.
At a press conference Monday, The X Factor's creator Simon Cowell praised the finalists and predicted that anything can happen as the show prepares to wrap its season Thursday night on Fox.
"This one here on my left [Carly Rose], I still don't believe she's human. The girls are a viable pop group now that could work in the same way as One Direction, and with Tate ... why he didn't get a record deal 20 years ago is ridiculous," Cowell said of the final three. "They're super, super talented and that's what it's all about. One of the best finals I've ever been involved in."
While L.A. Reid is leaving the show, Britney Spears gave no indication if she's returning next season. But the singer offered high praise for this year's final three.
"The whole experience has just opened me up to so many different things and just how many gifted people there are out there," Spears said.
Lovato says she likes the finalists so much, "I would collaborate literally with any of the contestants on this panel right now."
Reporting by PATRICK GOMEZ