Taylor Swift has teamed up with Carly Simon to sing the ultimate breakup song "You're So Vain". Being that every song Taylor Swift writes has everyone scrambling to figure out who she's singing about, I think it's it's a pretty great idea!

"Once we get out there and we have 55,000 in a sing-along, it's just going to be like karaoke night in the stadium," Swift, 23, explained to MTV News in a backstage video. "Every girl out there will be thinking of someone when we're singing."

Swift says that when she heard the song, she thought it was the best song ever written...