Katy Perry, surely you should be improving with all the practice you've been having promoting around Europe of late. So why is it that your latest rendition of Unconditionally at X-Factor UK was perhaps the worst you've had of the song thus far?
Effectively, you're only shading yourself getting on the stage of singing competitions- this one being the final of one, no less- and not being able to consistently maintain a tune. Take some vocal lessons, toute suite! And if you already are, get a better teacher for heavens sake! That is all.
[ Someone is doing their darnedest to remove any trace of this performance from the internet- seriously, it's almost as hard as finding a bad Hallmark movie (which is impossible, I'll have you know). Below is a clip from the Daily Mail, which will give you a taster, but the full thing can be seen here.]