Tamera Foster was hoping for a jaw-dropping performance and she got it although probably not in the way she wanted. The X Factor star forgot her words yet again when she took to the stage to perform James Arthur’s Impossible, originally sung by Shontelle. And let’s just say the judges weren’t too impressed. Louis said: “You have the potential to be a world class superstar but what happened to the words? You can’t do it anymore.” Gary went one step further, commenting that it was “hard to watch” before adding that the song was in the wrong key. http://www.youtube.com/watch?v=vqaTgqgpMKU Tamera's performance on last night's show [Video via YouTube/ The X Factor UK]