Taylor Swift and Kendrick Lamar Mash-Up Hits the Web

— -- When Taylor Swift's album "1989" sold 1.287 million records in its first week, she celebrated by lip syncing the Kendrick Lamar rap, "Backstreet Freestyle."

Now, a mash-up of the song mixed with her hit, "Shake It Off" has hit the web. (Listen to it here, but note that there is some explicit language.)

"Industry experts predicted 1989 would sell 650k first week. You went and bought 1.287 million albums. AND IT'S GOT ME LIKE," Swift wrote on Instagram last week -- a lead-in to a video of her mouthing the words to Lamar's song. Sample lyric? "Goddaamn, I feel amazing, damn I'm in the matrix/My mind is living on cloud nine and this nine is never on vacation."

It's been a big week for Swift, as her video for "Blank Space" was released just two days ago. In the video, Swift, 24, plays a crazed ex-girlfriend, which video director Joseph Kahn told Mashable was a take on the singer's much-discussed dating history.

"She's aware of this. She's not an idiot," he said. "Taylor wanted to make a video addressing this concept of, if she has so many boys breaking up with her maybe the problem isn't the boy. Maybe the problem is her."