That was done in 2013. It'd probably be the same songs again if the theme were brought back!

No Whitney and no annoying Beyoncé songs allowed week

Joe Pasquali week!

Each contestant comes on and sings his "I know a song that'll get on your nerves, get on your nerves, get on your nerves..." song.

Unplugged
Madonna

Id like a raw sewage week....

2015 songs week

I would say classic rock, but they'd only make an absolute arse of it. Cheryl, Rita and Nick wouldn't have a clue about the genre.

Didn't they have a previous Rock week and there was a song that Cheryl had never heard of

Talent show winners week
One hit wonders week
Tom jones week

British songs from 2015

Acapella week.

No backing tracks, no fireworks, no choirs, no pretending that jumping around is a form of singing.

Just stand there and let's hear what you really sound like.

That definitely rings a bell...but I haven't a clue which song it was and there doesn't appear to have been a Rock Week last year.

LIP SYNC... FOR YOUR LIFE week

The winner is the one who does the best job lip syncing to a Cheryl track, cos we all know even she is incapable of that.

It wan't last year, and I'm not even sure it was Cheryl. The trouble is after so many years each series seems to merge (for me anyway)

I know it was a well known song and everyone was amazed that the judge in question had never heard of it (I'm sure it was a female judge).

It's bugging me now

EDIT:

I've just checked X Factor songs from 2010.

On week 6 Paige sang 'Crocodile Rock' - was that it

Yes it was, and it was Cheryl

https://www.youtube.com/watch?v=UBVwKd0QIbQ

That picture is the wrong way round as the judges are in the wrong seats