Rihanna explains why she collaborated with Chris Brown

Many have been wondering why Rihanna would do a musical collaboration why her ex Chris Brown based on what happened during their relationship.

This morning Rihanna called the Ryan Seacrest this morning on KIIS FM to explain why she collaborated with Chris Brown.

"I reached out to him about doing ‘Birthday Cake’ because that’s the only person that really -- it made sense to do the record. Just as a musician -- despite everything else -- that was going to be the person."

Rihanna says it was her idea for Brown to appear on her song because he’s “the hottest R&B artist” right now.

"I thought about rappers, and I’ve done that so many times, and the hottest R&B artist out right now is Chris Brown. So I wanted him on the track."

Brown appears on a remix of her song Birthday Cake and she appears on a remix of his Turn up the Music