Last week, the Top 32 ‘X Factor‘ contenders received their mentors, judges and guest judges. Rihanna gave her input to L.A. Reid while Enrique Iglesias piped in with Nicole Scherzinger and Simon Cowell flew solo. This week, the remaining 16 contestants sang their hearts out for a shot at fame and $5 million.

Here’s what went down this week. Be sure to tune in for eliminations on Tuesday!

Nicole ScherzingerThe Over ’30s

The former Pussycat Doll and guest judge Enrique Iglesias made the sultriest panel, but Iglesias was almost as quiet as Mariah Carey–who didn’t even make it to be Simon’s partner!

Josh Krajcik: His deep voice and husky appearance make him a standout, which can only help him — not that he should need much, considering his performance of ‘The First Time Ever I Saw Your Face‘ moved Nicole Scherzinger to tears. When asked if he’s prepared to go back to making burritos for a living, Krajcik replied, “I’m not ready to go back to that.” Good, because we’re not ready to see him go!

Leroy Bell: The oldest contestant (he’s 60 — but looks a good 20 years younger) sang ‘Make You Feel My Love‘ by Bob Dylan. Bell has a smoky, almost  Springsteen-like quality to his voice, but his experience doesn’t quell his intimidation by the judges. “His nerves make him hold back from giving me everything,” Nicole Scherzinger said. Fear not, though — he has something helping him. “He’s so cool,” Scherzinger sighed.He’s just the coolest.”

Tiger Budbill: The wedding DJ sang ‘Don’t Give Up On Me,’ likely to drive home how badly he wants to move forward. Scherzinger was torn, though. ”His voice, it’s effortless for him — do you think there’s a market for him?” she asked Enrique Iglesias. “Do you think he could sell records?” Time will tell.

Christa Collins: The tattooed former Disney prodigy has a theatrical quality and is fun to watch — but can she actually sing that well? Her performance of Radiohead’s ‘No Surprises‘ left a bit to be desired vocally, but her passion was palpable. While Enrique Iglesias liked her, Scherzinger noted, “I would’ve liked to see a little more pain, a little more of those emotions.”

Simon Cowell The Girls

With his partner, Mariah Carey, grounded due to Hurricane Irene, Cowell was left to fend for himself. He fared just fine (like anyone would’ve thought otherwise!), but would it kill him to button his shirt a little more?

Jazzlyn Little: Her voice is good, but the jazzy, slower version of Gloria Gaynor’s ‘I Will Survive‘  doesn’t do her that much justice. Her audition proved that she is capable of much more than this. Here’s hoping her song choice doesn’t hurt her chances.

Rachel Crow: The adorable 13-year-old sang a slowed down version of the Backstreet Boys‘ ‘I Want It That Way‘ so intensely that she almost looked angry — but as soon as the song was over, she was back to being sunny and precocious. “That was unbelievable,” Simon said incredulously. “I like the fact that she takes risks, and I like that deep tone. That’s the part that excited me,” Simon said. “Maybe it’s just bad luck that she’s in this category.” For her part, Crow was justifiably confident. “Hopefully I make sure I step up my game,” she said. “And whatever happens, it will be epic.”

Tiah Tolliver: Tolliver sang a soul-infused version of ‘No Diggity‘ by Blackstreet and absolutely killed it. Improving a great deal from her first audition, her combination of raw talent and unique approach make her a force to be reckoned with. “There’s something about her,” Cowell said. “I just feel like she belongs in this competition.” He’s right.

Melanie Amaro: Amaro is an undisputed vocal powerhouse, so it’s no wonder producers saved her for last. She sang ‘Will You Be There‘ by Michael Jackson and sounded exactly how you’d expect: Incredible. Simon feigned fainting at the conclusion of her performance. Simon’s only qualm is that she didn’t leave her comfort zone, but with a voice like hers, her comfort zone is probably huge.

L.A. Reid + The Boys

Guest judge Rihanna had the most input of all the guest judges this episode, but having her judge the boys seems like a cruel trick–as if L.A. Reid wasn’t scary enough, you have Ri-Ri making the boys weak in the knees to boot!

Brennin Hunt: “I want to be bigger than Lady Gaga,” Hunt said. Then Hunt needs to rip a page from Lady Gaga’s book and make himself stand out. Sure, he’s good looking, but that doesn’t necessarily mean he’ll be on the Billboard charts after his performance of Corinne Bailey Rae’s ‘Like a Star.’ While Rihanna said he’s “beautiful” and complimented his tone, when L.A. Reid asked, “Does he sing like a star?” she admitted she couldn’t decide. If Rihanna can’t decide, America may have an even bigger problem later on.

Tim Cifers: The Southern sweetie pie sang a moving, country rendition of  ’Dance With My Father‘ by Luther Vandross. “I really liked his voice,” Rihanna said. “He’s a real country singer.” While many viewers may have been moved to tears, L.A. Reid wasn’t one of them. “It was good, but I wanted more. I wanted so much more from him.”

Marcus Canty: He may have been Rihanna’s favorite — they even flirted a little! (Was he trying to hedge his bets?) Canty covered ‘All My Life‘ by K-Ci and JoJo, singing right to the pop chanteuse the whole time. “I’m gonna cry!” Rihanna yelped. “To see how confident he was—he looked right in my eyes. I felt good about that performance.” But Rihanna and L.A. Reid were still “not convinced” of his star power. They might be nuts — he’s amazing!

Chris Rene: The newly clean Chris Rene sang a hip-hop version of ‘Everyday People’ by Sly and the Family Stone, and Rihanna looked mesmerized. “He has something very special,” she said. “I want to know more about him.” L.A. Reid agreed. “Whether he wins this $5 million doesn’t matter, as long as he stays true. I’ve just never seen him so nervous.” He nudged Rihanna. “Maybe you intimidated him!” As fierce as RiRi is, it’s unfair to pin all of Rene’s jitters on her with so much on the line.

Paula AbdulThe Groups

Rapper, singer, producer and one half of the Neptunes, Pharrell, joined Paula and provided valuable insight on the contestants in the group category. He’s a great fit–he’s made a career out of killer collaborations.

2 Squar’d: Per Paula’s suggestion, the girl group sang Queen‘s masterpiece, ‘Bohemian Rhapsody.’ The song isn’t easy by any means, and the vocals fell flat—which doesn’t bode well for them during live shows. Pharrell and Paula agreed the solos “were a little off,” so advancing this team wouldn’t end well for anyone.

The Stereo Hoggz: Their rendition of ‘Heard It Through the Grapevine‘ knocked it out of the park. From vocals to choreography, they’ve made massive improvements since auditions. Pharrell said it best: “That lead guy–he’s Motown mixed with Ginuwine.” Here’s hoping they can keep it up!

Illusion Confusion: Their cover of ‘Let’s Dance‘ by David Bowie dripped of a boy band vibe. It appeared more work went into choreography and coordinating outfits than into vocals. While Abdul and Pharrell admired their ambition, they both recognized that it would take more than motivation to win. And their name isn’t doing them any favors!

Intensity: The largest and youngest group performed ’That’s Not My Name‘ by the Ting Tings, and if they didn’t make you smile, you may not have a pulse. They’re talented and adorable–but the fact that there are just so many members may hinder them at some point, because there won’t always be enough solos to go around.

The judges spent the last few minutes of the show poring over performers and deliberating with their guests — but we’ll have to wait until Tuesday night for eliminations, where the Top 16 will be revealed. It’s definitely going to be close!