The X Factor 2015: Semi-final theme, Jason Derulo to perform and what acts will sing

We've reached the semi-final of the The X Factor and this week's theme "Songs To Get Me To The Final". The four remaining acts will be belting out tracks they hope will impress the audience enough to cement a place in the final while showcasing their vocal talents. We figured that's what they'd be doing anyway regardless but hey, all of the set themes have been a little vague this year to say the least.

Following on from the quarter-final, when Filipino girl band 4th Impact were eliminated from the competition, each act will have to perform two songs during the show on 5 December.

And on 6 December, only one act will be eliminated but that doesn't mean the acts can relax when it comes to their songs seeing as one super performance could earn them their place in the top three. Here's what you can expect from each of the remaining finalists...

The Boys - Judge: Nick Grimshaw

Grimshaw's sole remaining act Ché Chesterman will perform Love Is A Losing Game by Amy Winehouse and later, Charles & Eddie Would I Lie To You?

The Girls - Judge: Rita Ora

Lauren Murray is set to take on Runnin' (Lose It All) by Naughty Boy featuring Beyoncé and Arrow Benjamin, and Best Of My Love by The Emotions. Louisa Johnson will be channelling Frankie Goes To Hollywood as she sings The Power Of Love. Her second track will be It's A Man's Man's Man's World by James Brown.

The Groups - Judge: Cheryl Fernandez-Versini

Fernandez-Versini's self-confessed favourites, Reggie 'N' Bollie are her only act left and they will perform R City and Adam Levine's Locked Away and a mash-up of I Gotta Feeling and I Like To Move It by Black Eyed Peas and Reel 2 Real respectively.

According to William Hill, Johnson is the favourite to win for the sixth week running with odds of 1/3 and double act Reggie 'N' Bollie are in the runner-up spot with 11/2. Ché Chesterman is third and Lauren Murray is fourth. As the only judge with two acts left, it seems very plausible that Ora would come out on top.

Tune into The X Factor on ITV from 8pm on 5 December to see the semi-finalists perform their songs. The results show is on from 8pm on 6 December, where Australian electropop singer Sia will perform Alive from her latest album, This Is Acting. Meanwhile, Jason Derulo will sing Want To Want Me taken from his new record, Everything Is 4.

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