"The X Factor": Top 6 go unplugged

Six contestants remain on Fox's "The X Factor," and last night they all battled for a spot in next week's final four.

Instead of getting one shot to impress America, the contestants this week sang two songs -- one "unplugged" song and another one selected by viewers.

Demi Lovato's Young Adults

CeCe Frey kicked off the night singing an unplugged version of Lady Gaga's "Edge of Glory." Simon Cowell told Frey, "I don't think you're worth a $5 million recording contract." Britney Spears agreed, saying, "I think at this point in the competition it should be great, and it was just good for me."

For her second song, Frey sang "Part of Me" by Katy Perry. The judges liked Frey's rendition of the song better than her previous performance. Spears called it "entertaining," and Demi Lovato, Frey's mentor, said, "You made me proud."

Simon Cowell's Groups

Emblem3 sang Bruno Mars' "Just The Way You Are." Spears called the group's unplugged performance the best one "hands down," but Lovato disagreed saying, "it wasn't the best." Cowell backed his group saying they did "amazingly well."

For the second song, the boy band sang Jay-Z's "Forever Young." Lovato said, "I am a fan. I just want to see you command the stage more." Spears said, "I thought it was a superstar performance."

Fifth Harmony, Cowell's girl group, sang Adele's "Set Fire to the Rain." Reid said he didn't hear the harmony. Lovato agreed with Reid that the group "hasn't really clicked" but said maybe some of them should consider being solo artists.

The members of Fifth Harmoney then took on Lovato's "Give Your Heart a Break," which won all the judges over. "A friend of mine does this song very good. And so did you guys," said Spears. Lovato added, "You guys definitely sing it better than the original."

Britney Spears' Teens

Carly Rose Soneclar, who was number one after last week's elimination, sang Justin Bieber's "As Long as You Love Me." Her unplugged version of the pop song won her praise from the judges. "You sang it better than Justin Bieber," said Lovato. Spears said of Soneclar: "The most impressive thing about you is that each week you continue to make each song your own."

Soneclar next sang Beyonce's "If I Were a Boy," which brought down the house. Reid chanted "Car-ly! Car-ly!" along with the crowd. Cowell said, "Your vocals are amazing!"

Diamond White sang James Brown's "It's a Man's World." Lovato called the song choice "risky" but said White "pulled it off." Spears agreed that the song was risky but said White didn't just pull it off -- she "destroyed it."

For her second song White sang Rihanna's "Diamonds." Reid said he "didn't love it." Cowell said, "Overall I think you've had a good night."

L.A. Reid's Over 25's

Tate Stevens sang Bon Jovi's "Livin' on a Prayer." The judges were not fans of the song choice agreeing that Stevens needed to get back to his country roots. Spears said," I feel like you're getting away from what you do best." But Reid said, "I love the song. I think you did a really good job."

For his second song he went back to country, singing Garth Brooks' "If Tomorrow Never Comes." "That felt like a Tate Stevens performance," said Spears. Cowell said "Welcome back, Tate Stevens, to the competition."

"The X Factor" returns Thursday at 8 p.m. ET on Fox.