"I heard it and I always knew I wanted to write this futuristic, alienistic song, and I was like, 'Wait, I can wrap my head around this. I know this seems like a long shot, but I think I have the perfect material to put on top of this sound.' And I did, and it really worked out perfectly (sic)."
The single version of 'E.T.' which stands for Extra Terrestrial , features rapper Kanye West, and Perry admits he helped bring out the track's "urban feel".
She added: "It's kind of a bit harder, it does have that urban feel underneath it. I think that's why Kanye added even another layer on top of it.
"And it has amazing sonics - I mean, there's so much to it, there's a lot in the song if you really put your headphones on and sink into the song."
Watch katy perry video ::(firework)