Calvin Harris has spoken out about his upcoming collaboration with Katy Perry.

The star is currently number one in the midweek charts, and has booked in studio time with Perry for December.

"She wants to go in with no pre-planning but I'm the sort of guy who wants to turn up with nine or ten instrumentals and play them to her to see what she thinks. I think I'm going to do that regardless and see what happens. I'm looking forward to working with her - she's a normal person and she's not up her own a**e the way a lot of these American popstars are."

Harris, who has also produced tracks for Dizzee Rascal, Kylie Minogue and Sophie Ellis-Bextor, admitted that he leapt at the chance to work with the US singer.

"Katy Perry's an amazing popstar and when I heard she wanted to work with me I was like, 'What?! F**king definitely!'" he said.