The track is called "Bad Blood" and it is the product of years of abuse at the hand of an unnamed female artist.

So who is it? Taylor says that this star only offers nasty, backhanded compliments and has made Taylor question, "Are we friends, or did she just give me the harshest insult of my life?”

Taylor said that the other stay basically tried to sabotage a entire arena tour last year, hiring a bunch of people out from under her.

Angry Taylor.

Taylor isn't naming anyone, but it could be Katy Perry.

Three of Taylor's back-up dancers, Scott Myrick, Lockhart Brownlie and Leah Adler went to work for Katy Perry while in the middle of a tour with Taylor.

Taylor got pissed, so she took a jab at Katy during the height of the Roar plagiarism scandal. Taylor invited Sara on stage to sing the song in question, calling it "so original."

The two of them have been linked to John Mayer. Taylor says that it's gotten so awkward, it's hard to imagine if they'll be better after 1989 drops on October 27.

Don't you just want to hear the track now? Why didn't Taylor just shake it off?