Before the end of Sunday night's results show (2 November), Disco Fever was confirmed as the new theme, but it was scrapped following a last-minute meeting late last night.
Simon Cowell, Cheryl Fernandez-Versini, Mel B and Louis Walsh decided to scrap Disco Fever in favour of Queen versus Michael Jackson.
Leaving a meeting with the judges just after midnight, the show's executive producer Mark Sidaway, tweeted: "Just leaving a song meeting with all the judges. Okay, hold into your hats, we may have a theme change."
Minutes later, Mark confirmed: "Disco just died. We've a new theme coming..."
Fans were then told that the new theme will be "based on two iconic acts", and it wasn't long before X Factor made the announcement to its millions of followers via Twitter.
This weekend's Fright Night-themed show saw Jack Walton and Lola Saunders eliminated from the singing competition. Meanwhile, John Legend and judge Cheryl Fernandez-Versini were guest performers.
Next weekend, One Direction and Sam Smith will be gracing the stage for a live performance.
X Factor continues on Saturday at 8pm on ITV.
Reveal is now on Google Plus! Join us here for the latest pictures, fashion and celebrity news!