Taylor Swift performs in American Music Award After winning

Taylor Swift sat at her piano on the American Music Awards stage and sang "Back to December." Violinists joined her on the set, which was dressed with Christmas lights on tree branches.

Swift sang her heart out during the Speak Now ballad about messing up a relationship and say sorry for it. Midway through the song, snow fell on the stage as the stage lights came up showing her band.

Many of the elements of the performance felt similar to the ones she used during her CMA Awards performance previous this month. But this time, the AMA winner changed things up a bit, and before the song ended, she played around with the theme of the song by singing part of OneRepublic's "Apologize" as she stood up and over up the tune.

"So this is me ingesting my pride/ Standing in front of you saying 'I'm sorry' for that night/ And I go back to December all the time/ It turns out freedom ain't nothing/ Missing you, wishing I'd realized what I had when you were mine/ I'd go back to December, turn around and make it all right/ I go back to December all the time," Swift sang in the chorus.

Swift was the second pop star of the night to do from behind the piano. Earlier in the night, fellow AMA winner Justin Bieber sat behind the piano for his performance of the new song "Pray." While Swift chose for snow to bolster her performance, Bieber included a choir.