What made The X-Factor's Redfoo cry?

LFMAO star Redfoo says he's "going through something right now in a relationship" and this contestant's song got to him. What was it?

X-Factor

REDFOO, you superstar. Not only can you wear all of the colours at once, you can sing, dance, and deliver possibly the best line heard on TV this year.

When a brilliantly awkward dancer (and perhaps the world's worst singer) got voted off, he proudly declared "Don't forget the name John Roubos, you're going to hear it in the near future."

The LMFAO singer quickly joked, "Hopefully not in the news."

Redfoo wasn't the only star on the first night of Channel 7's answer to The Voice.

X-Factor

Opening with two acts that were heavily promoted leading up to the premiere of this year's X Factor, the show was clearly setting out to hook people early on; with the opening night up against Channel Nine's premiere of Big Brother.

First up we met 14-year-old Jai Waetford. With the floppy hair thing going on, there were plenty of screams and tears from the teenage girls in the audience.

And the tears continued when he sang an original song "Don't let me go".

Redfoo surprisingly admitted the lyrics got to him.

"I'm going through something right now in a relationship. And those lyrics made me cry.

"I wish I could show this to her now."

Although he didn't mention her by name, Redfoo has been dating tennis player Victoria Azarenka.

Next up, we had another heavily promoted act, Kelebek. She explains her name is really Vanessa, but Kelebek is Turkish for "butterfly" which sounds cool. OK then.

This isn't the 17-year-old's first time on The X Factor, making it through to the top 24 in last year's boot camp. She explains she couldn't handle the pressure then, but is hoping to give it another go this year.

After a knock-out performance of Flo Rida's "Good Feeling", it's clear Kelebek is getting her second chance. And then she gets to dance with Redfoo; so we're all pumped for her to do well.

Redfoo meets John Roubos

Channel Seven's producers have also done well finding their "heart-string" stories this year.

First up we've got Tyler Hudson, who has a son with autism and a wife about to give birth. Cue the sentimental music.

The Texan-Australian doesn't blow the judges away, but he puts in a solid enough effort to get through.

We've then got Swedish brothers JTR who've just landed in Australia from Sweden, specifically so they could audition. Well, that, and to see their mum who's married to an Australian.

Ronan Keating nervously says "I hope they're good" before the boy-band looking group launch into their act. They are good. Of course. And Ronan declares they "have the X Factor". Dannii reckons they've got "the potential to be global superstars".

The show then puts together a montage of very strange and bad Psy impersonators. Moral of the story, if you want to get through on the X Factor, don't try and be Psy.

Slightly awkwardly, they then trot out K-Pop fan Dami Im. She has cats on her stockings, and looks like she's about to launch into another Psy rendition.

But the 24-year-old Brisbane woman surprises everyone with a powerful rendition of Mariah Carey's Hero, and guess what - she's through to the next round.

We're then back to another "heart-tug" moment when Ellie Lovegrove tells her story. She's an indigenous teen from Adelaide, and wants to tell young Aboriginal kids "anything is possible if you put your mind to it". She got her musical talent from her dad, who died when she was ten. Sad music in the background, we hear more about her journey.

Luckily her voice is as strong as her story, with Lovegrove getting a standing ovation for her rendition of "This Girl Is On Fire".

Veanka Howard

The final heart-string moment comes from 15-year-old Veanka Howard from Yass. Like last year's Voice winner Karise Eden, she has lived in foster homes most of her life, but has found her "parents" in the last five years, who taught her to sing to "get the anger out".

Nat Bass is clearly on side before she starts to perform.

"It's daunting up there, but enjoy it. We want you to be great as well".

Of course, she's great. Everyone's in tears, especially Howard herself at the end of the song. Her mum comes out on stage to comfort her as she gets four yeses from all the judges.

And in a night where we've seen lots of tears, she is clearly being built up to be this year's "story".

The X Factor night one is finished - but not before a quick promo to the next two nights, where we're looking to see a girl band with attitude, and a group who want to be the next Black Eyed Peas.