Katy Perry has revealed that she always knew her latest tracks should sit well with her audience.

The US star has so far unleashed three songs from her upcoming album 'Prism' - 'Roar', 'Dark Horse' and 'Walking on Air'.

She premiered some more at the iTunes Festival in London last night (September 30), such as 'By the Grace of God' - and she told Capital FM that she was confident the songs would sit well with her audience. She said:

"I knew that they would resonate, I knew that they were real, I knew that people would really relate to them. My main purpose really is to relate to people through songs and for them to get inspired and feel some hope."

Speaking meanwhile about her decision to play the one-off iTunes Festival date, Perry said:

"How could I ever leave out the UK? I love a Sunday roast, so I'm never going to miss the UK. And not just because of the baked beans, the Sunday roasts and the great fans!"

The pop songstress meanwhile will release her new album 'Prism' on October 21 in the UK and a day later in the US