It was recently revealed that Brandy's next single "Put It Down" would be a collaboration with Chris Brown. Which explains a seemingly random Tweet by Chris a few weeks ago and what appears to be a desperate attempt by Rihanna to get his attention...
Chris Brown randomly Tweeted that Brandy was the best female vocalist, leaving fans scratching their heads and speculating whether or not Chris and Brandy were in the studio together.
Shortly after Chris Tweeted about Brandy, Rihanna, who was also in LA at the time, randomly tweeted some Brandy praise of her own causing Chris to delete his Brandy Tweet altogether. Rihanna is always being messy.