Katy Perry sang a brand new song at Sunday night's Grammy Awards, and boy was it personal!

The song, titled Part of Me, is all about a bitter breakup and is clearly Perry's way of expressing her feelings about her divorce from Russell Brand. And with Perry choosing to debut the song on the biggest music stage in the world, it's no doubt she wanted him to hear her. Check out some of the songs lyrics after the jump!

Katy Perry is sooooo ready for her marriage to Russell Brand to be over! Radaronline.com has obtained the court documents finalizing the split between the former couple and it seems that Perry wanted everyone to know how excited she was to be signing the papers -- she added a smiley face next to her signature!

Although, she does have a right to be pretty happy, as she will not have to give any financial support to her ex-hubby, despite the fact that they did not have a prenup.

And we thought the Grammy’s couldn’t get any better! Yesterday we reported that Adele had been added to the performing lineup during the big night, but now another big name will also be taking the stage – Katy Perry!

Yes, that’s right! Not only will this be one of her first public appearances, but televised performance since her very public split from Russell Brand.

Katy finished up her California Dreams world tour a couple weeks ago and has been pretty much MIA when it comes to public appearances.