Leona Lewis is a closet rock chick.

The 'Bleeding Love' singer has revealed she loves listening to bands like Radiohead and Foo Fighters as well as heavy metal stars System of a Down.

She said: "I love Radiohead. They are so innovative. I still believe they are way ahead of their time. I'm into a lot of rock music, not just pop. I've been listening to a lot of System of a Down, Foo Fighters and Snow Patrol lately."

Leona has also thanked the big music stars who came forward to work with her on the U.S. version of her debut album 'Spirit', which hit shelves on Tuesday..

She said: "I was able to work with so many talented artists like Akon, Ne-Yo and Ryan Tedder. It also means so much to me that artists like Beyonce Knowles, Mariah Carey and Rihanna, who didn't even know who I was a few months back, took time to write on the record."

Ged Doherty, the Chief Executive Officer (CEO) of Leona's label Sony BMG, recently predicted: "I think Leona will be the biggest new artist in the U.S. this year."

'Spirit' is expected to sell 200,000 copies and could debut at number one in the U.S. Billboard album charts.