AceShowbiz -

Katy Perry's never-heard-before track called "Part of Me" has just surfaced. The 26-year-old singer resents an unnamed ex-boyfriend in this pop/rock song, talking about walking out of his life with head held high and stating that he won't ever bring her down.

"Days like this I want to drive away/ Pack my bags and watch your shadow fade/ 'Cause you chewed me up and spit me out/ Like I was poison in your mouth/ You took my light, you drink me down/ That was then and this is now, now look at me," she sings. "This is the part of me that you're never gonna ever take away from me."

The song reportedly comes from production hands of duo top-notch music makers Max Martin and Dr. Luke. It is allegedly an unreleased track from Perry's summer album "Teenage Dream" and will be added to the re-release package which is expected to come out next year.

In the meantime, the next single from the album is ready to roll out. It's reportedly a futuristic single called "E.T." which recently got a remix featuring British rising star Tinie Tempah. The song was chosen based on fans' advice. "Thanks for all your great suggestions for the next single today!" she wrote on her Twitter. "Your voice has been heard! We're on the same page..."