WATCH: Katy Perry Performs ‘By The Grace of God’ at iTunes Festival 2013 [VIDEO]

http://youtu.be/mEW2NfZUQLw

Last night, Katy Perry performed a new song called “By The Grace of God,” which is a breakup ballad off her upcoming album “Prism.” Many think it has to do with her highly publicized divorce from Russell Brand. Watch the heartfelt video of her performance.