Mike Coppola / Dimitrios Kambouris, Getty Images

Alicia Keys and Maxwell's collaboration, 'Fire We Make,' is heating up the charts and the two superstar singers are going back to the studio to create some more magic with an EP of duets.

Maxwell revealed the details on the joint project to Billboard. "We're definitely working on an EP that's sort of Marvin Gaye/Tammi Terrell," he shared.

The album seemed inevitable as the singer revealed that he and Keys go way back, calling her his "little sister."

"We got a thing musically," explained Maxwell. "That's like my little sister. What's funny is Swizz [Beatz] is the champion of all of it… She's someone that I trust. I'm like that, by the way. Most of the people you see working for me are actually with me. And I'm proud to say that I've known them 20 years almost."

In the meantime, Maxwell is putting the finishing touches on 'Blacksummers'night,' a long-awaited LP expected to hit shelves by the end of the summer.

Watch Alicia Keys & Maxwell's 'Fire We Make' Video