Music mogul Simon Cowell has admitted that he was incredibly nervous to launch X Factor USA and worried that the ratings would see the show fail. 

Speaking to the Evening Standard, Cowell explained that his self-set target of attracting 20 million viewers for the talent contest's debut series caused him a lot of stress and he wouldn't even celebrate the first episode's airing in case it bombed:

"I wasn't opening any champagne on the first day because now we had set everyone's expectations. The worse thing was in the second day because if you have a 30 or 40 per cent drop off, you're dead."

"And in fact somebody said to me, 'If this drops off 30 per cent Simon, it's probably going to be all over.' That is when I was tense."

Luckily for Cowell, the show has been a success and he has since relaxed about the initial pressure so can now enjoy the process:

"As much as people want you to succeed, there's a ton of people that want you to fail and I took a bit in the neck that first day. But I always trust the public and I get a feel for the show and it's been positive and starting to grow now."

Watch 14-year-old bootcamp star Rachel Crow perform a stunning rendition of Beyoncé's 'If I Were A Boy' below: