Katy Perry has admitted that despite scoring several high charting singles from her Teenage Dream album, she worries if she will be able to repeat the success again.

The pop superstar, who is currently working on the follow-up, told US Vogue: ''When I am in between records, sometimes I doubt myself. I'll be like, 'Did I just get lucky, or did I mass-manipulate the world into thinking that seven songs were worth a number-one position?'"

''And then I go back into the studio and I start writing, and the true essential oil of who I am comes bubbling back up and reminds me that it's always been inside of me, that nobody can take this away no matter what comment anyone makes. It's going to be there because it's what I was born with and it's what I've worked on my whole life.''

While Katy didn’t confirm how much of her new album is written, she did talk about on track in particular called Bad Photographs.

She said: ''I titled it Bad Photographs because the idea is that when people are in a relationship they only take photographs when they are happy, and sometimes when it ends you realise maybe it would be important to take photographs when it's not happy".

''So I have this idea, 'Looking back we should have taken photographs / of all the unhappiness / because now my mind's playing tricks on me / I forget we are not meant to be.''