As the opening track of the influential Black Sabbath album, Paranoid, “War Pigs” was originally titled “Walpurgis.” Walpurgis Night takes place on the 30th April to mark the eve of the feast day of Saint Walpurga, an 8th-century English missionary to the Frankish Empire. It is also believed to be the night of a witches’ meeting or sabbath. The instrumental outro is entitled, “Luke’s Wall.” It is one of the most-covered songs in history and is frequently ranked among the greatest rock songs of all time.

The song talks about war and—like the hippies—Black Sabbath was totally against it, specifically the Vietnam War (occurring at the time), and although Geezer Butler has stated that:

[“War Pigs” is] totally against the Vietnam War, about how these rich politicians and rich people start all the wars for their benefit and get all the poor people to die for them.

And in an interview with Mojo in 2017:

Britain was on the verge of being brought into it, there was protests in the street, all kinds of anti-Vietnam things going on. War is the real Satanism. Politicians are the real Satanists. That’s what I was trying to say.

Ozzy Osbourne has said that:

[The group] knew nothing about Vietnam. It’s just an anti-war song.

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”.