Ok. I'm a new judge here, taking over smi's role:
GLEE - Not the best song you could have chosen, but something that should keep you safe.
Katy Perry - Loved the song, quite limited to what you could have chosen but all round perhaps the best choice.
Britney Spears - Surprised with this song choice, but an extremely catchy song. Fitted in with the dance theme moderately well. Improvements could still be made.
Savannah Outen - Absolutely awful. First 30 seconds has nothing to do with the song, it concentrates on two young cute boys. The song gets quite annoying too, definetely a better choice could have been made here.
The Script - Better songs could have been chosen and this probably doesn't fit into the theme best. Still a fantastic song.
P!nk - Best of the show so far, great song choice and executed well. It is an amazing song which always helps.
Rihanna - My own act. A great song and fits into the theme very well. Brilliant choice.
Enrique Iglesias - Not much you could have chosen to go wrong here. Great song, great vocals and well executed.
Alexandra Burke - This didn't work for me. It was a bit too predictable, a safe choice but lack of enthusiasm.
Beyonce - Impressive, I was expected something pretty average but it was a good performance overall.
Bon Jovi - Fantastic choice of song to fit the theme. Definetely one of the best so far. I'd be extremely shocked if this was put in the bottom two.
Celine Dion - Very slow song, and I expect that from this act. Perhaps a 'dance' theme isn't best for an act such as Celine Dion. I wouldn't be surprised if we see this in the bottom two
Nicki Minaj - New to me, but different to the others. There is a spark of genius in this and I expect you to go a long way in this show. Absolutely brilliant.
Christina Aguilera - A good performance and perhaps the best song you could have chosen for this theme. Well done.