Video: Taylor Swift & Justin Bieber perform “Baby”

Taylor Swift surprised her audience at last night at the Staples Center in Los Angeles.  She was singing a cover of Justin Bieber’s hit song “Baby,” but the surpise came when he joined her onstage to finish out the song!

Taylor Tweeted to tell her followers about her duet:

“You think you’ve heard LOUD screaming in your life.T hen @justinbieber comes out and does a surprise song during your show. Woah. Unreal.”

We tend to agree!  Check out the video…and yes, you can hear MOST of the singing through the screams.