Taylor Swift expresses her guilt in “I Knew You Were Trouble” due to a relationship destined to fail. With its sound playing between electropop and dubstep, this song marks the significant period in which Swift began to move further away from her country roots and into more pop influences. TIME congratulated Swift on being “the first major artist to fuse country and dubstep.”

It was originally released on October 9, 2012 as the third promo single from Red, and later as an official single on November 27, 2012.

The song was an international commercial success, charting as a top ten hit in more than a dozen countries. In the U.S., it debuted at number three, mainly due to digital sales of 416,000. Later, it peaked at number two, becoming one of her many top-two hits including “You Belong with Me” and “Today Was a Fairytale.”. As of 2019, the song has sold 5.42 million copies in the United States.

The hidden message for the track is “When you saw me dancing”, which leads to speculation that the song is about Harry Styles — whom Taylor is said to have first met backstage at the 2012 Kids Choice Awards.

Her and Selena Gomez were seen dancing to One Direction’s performance of “What Makes You Beautiful”.