Katy Perry beats Gaga in the singles race, but Britney may best them both

Hear that "Roar?"

That's the sound of Katy Perry's new single with that title blowing by Lady Gaga's new single "Applause."

According to Billboard, Perry is on track to sell 525,000 to 550,000 downloads of her song while Gaga is projected to sell between 200,000 and 225,000. The official numbers will be released on Wednesday.

And not only do the pair have the charts in common, but they also will be taking to the airwaves for the same event. Gaga will open the MTV Video Music Awards on Sunday and Perry is also scheduled to perform. Perry's collaborator, Bonnie McKee, told MTV that her friend's new single is just a preview of what to expect from her upcoming album, Prism, which will be released in October.

"It's kind of like every song is its own little movie, so this is 'Rocky' and also kind of jungle-y and cat-themed,"McKee said. "And then each song has its own little movie and its own visual to go along with it."

So the battle of the pop princesses rages on, though they both may need to watch their backs.

That's because it's Britney...we won't say the word, but Britney Spears is getting fans ready for something with a countdown clock that has now taken over on her official site and the words "All Eyes On Me." Fans can sign up for mailing list that we suppose will deliver news of what folks are predicting will be information about her upcoming album.