Be warned, Kanye: Taylor Swift has written a song about you, and she's singing it at Sunday's MTV Video Music Awards.

The country superstar's win for best female video last year was marred when Kanye West got on stage and said it should have gone to Beyoncé. Swift wrote a song about the experience earlier this year, and a source familiar with the show said Saturday the 20-year-old will sing the new song at the VMAs, which will be aired live on MTV. The source did not want to be identified because of the sensitivity of the matter.

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The song is on Swift's upcoming album "Speak Now," due out in October. The source said Swift performed it during a secret rehearsal in Los Angeles for the VMAs on Friday.

Though the West-Swift moment only lasted but a few minutes, it has endured for what seems to be a lifetime. It became a cultural watershed moment and gave West the most intense backlash of his career, despite an apology delivered later.

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He dropped out of the spotlight, and last week on Twitter, said that he endured death wishes, had to cancel a tour and let go of employees. He again apologized to Swift and said he wrote a song for her and hoped she would sing it - and if not, he would perform it for her. But instead, Swift will be singing her own song.

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The Grammy-winner is known for writing intensely personal songs, and skewering a few former boyfriends along the way.

After initially expressing her hurt, Swift has avoided addressing the matter.

West will also be a performer at the awards show; both are nominees. It's not clear what song he will sing.

Though there was anticipation of possible fireworks related to last year with West's performance, Swift's song all but guarantees it.