Sonneclar, who was No. 2 in viewer votes a week ago after finishing first for two weeks, chose Elton John's "Your Song" for her first performance, while her mentor, Britney Spears, picked "Imagine" by John Lennon for her second.
Simon Cowell, a judge with two acts left in the competition, said that Sonenclar sang the Elton John song beautifully but it wasn’t her best performance. "I think you can do better than that," the Emblem3 and Fifth Harmony mentor said.
Demi Lovato, an impartial judge with no acts left, called the song selection predictable but said that Sonenclar turned it around. "You walked out on stage and I was like, 'OK, here we go again. Another slow song,'" Lovato said. "Having said that, I think that this was my favorite song that you've performed."
"The R&B side to your voice, it was so magical. I don't care if it was predictable, it was great," she added.
L.A. Reid, mentor for No. 1 act Tate Stevens, echoed Lovato's praise for the Elton John rendition: "You did things with that song I've never heard done before."
Sonenclar started her second performance playing the piano for the first time on the show before rising to sing to the audience. She said in a pre-show clip that playing while singing made her nervous. But judges said the risk paid off.
"You've taken your artistic credibility up one notch by playing the piano," Reid said.
Lovato backed off her "predictable" comments from earlier in the show and called the second performance "amazing."
Cowell, however, had another uncharacteristic critique for Sonenclar, whom he previously called a "star in the making."
"When you hit those big notes, it was great," Cowell said. "But I'm not sure that song needs those big notes. I just didn't like the arrangement."
Spears disagreed with Cowell and said that Sonenclar was gearing up for a larger platform in her career as an artist. "I feel like it is time for you to go beyond this stage and compete with the biggest stars in the world," Spears said.
"X Factor" returns tomorrow night at 8 p.m., when three of the Top 4 acts will advance to the finals next week.
Mamaroneck, do you think Sonenclar will make it to the finals? Sound off in the comments section below.
Click here to sign up for Daily Voice's free daily emails and news alerts.