The dubstep singer has teamed up with the songwriter - who has previously worked with Robbie Williams, Katie Melua and Charlotte Church - to work on tracks for the follow-up to her debut, 'On a Mission'.
22-year-old Katy shot to fame last year after she was nominated for the Barclaycard Mercury Prize and has previously told how her backing band can be a little protective of her at live performances, especially when she gets approached by boys.
She said: "When I was playing clubs it would be all sweaty boys on ecstasy at The Front calling my name. So I'd be like, 'OK, I've gotta go now, find my mates,' but my band are all like my bl***y brothers, they're like the mafia around me, so I'm alright."
The 'Lights On' hitmaker also acknowledges being sexy is part of her image since she has "scrubbed up," but doesn't want people to only listen to her just because of the way she looks.
She said: "I've scrubbed up a bit, I used to go on stage in an old jumper, but I don't want someone to like my music because they feel attracted to me. Or, like I'm hot or something, that's not what I'm about at all. I don't care."