Fresh off his performance with the Black Eyed Peas at Sunday’s Super Bowl Halftime Show, will.i.am hit the studio with Britney Spears to work on her upcoming album Femme Fatale.

While walking the red carpet at the L.A. premiere of Justin Bieber: Never Say Never on Tuesday, the BEP frontman revealed that he’s giving the pop siren a rougher edge. “It’s mean, but a nice mean,” he told Extra of their collaboration. “It’s hard, but melodic. It’s aggressive, but smooth. It’s the next level, but today. She’s a sweetheart.”

Will admitted that their chemistry is what made the process simple. “We made music and that’s what I like,” he shared. “When you’re doing things because you just love it, without the, ya know, ‘We need a single’ pressure, when you’re just in there having fun, that’s what I love.”

Spears’ seventh studio album Femme Fatale features contributions from Dr. Luke and Max Martin. Find out if her work with will.i.am made the cut when the project arrives March 29.