Taylor Swift and Carly Simon performed Simon's hit, You're So Vain at Swift's concert at Gillette Stadium in Foxborough, Massachusetts.
You're So Vain was released in 1972. The song has been the source of a lot of speculation over the years. Even Swift wanted to know who the song was about. She asked the question when she introduced Simon to the crowd.
Got to sing 'You're So Vain' with Carly Simon at Gillette Stadium tonight!!!!! Unreal. I could not possibly look up to her more.— Taylor Swift (@taylorswift13) July 28, 2013