Rihanna and Chris Brown

Rihanna  and Chris Brown caused waves last month when the exes released not one, but two musical collaborations. Despite their rocky past — which includes Brown's pleading guilty to assaulting and making threats to his then-girlfriend — Rihanna says he was always the right person for the job.

"I reached out to him about doing [the song] 'Birthday Cake' because that's the only person that really... it made sense to do the record," she told Ryan Seacrest on his morning radio show Thursday. "Just as a musician, despite everything else, that was going to be the person." After pleading guilty to assault in 2009, Brown was sentenced to community labor and five years' probation. The court-ordered restraining order that prevented him from being near Rihanna was reduced a year ago, allowing the two to be in the same room and also talk to one another.

Chris Brown and Rihanna reunite — for a song collaboration

Brown can be heard on a remixed version of Rihanna's track "Birthday Cake." "I thought about rappers, and I've done that so many times, and the hottest R&B artist out right now is Chris Brown," she said. "So I wanted him on the track."

After she asked him to work together, Brown quickly asked her to do the same. Rihanna is featured on his song, "Turn Up The Music." "We did two records. One for my fans. One for his fans, and that way our fans can come together," she said. "There shouldn't be a divide, you know? It's music, and it's innocent."

Do you agree with Rihanna?