Carly Simon Tells Taylor Swift Who the Song "You're So Vain" Is About, But They Don't Tell Us

TMZ: Carly Simon told Taylor Swift who her infamous breakup revenge song is about ... and that was a terrible idea because Taylor Swift is a blabbermouth!

On July 27th, 2013, at the second of two sold-out shows in Gillette Stadium, Taylor gave the crowd a huge surprise! In front of more than 55,000 fans in Foxborough, Massachusetts, she introduced one of her heroes -- Carly Simon. They performed Carly's iconic hit song "You're So Vain" together, delighting the crowd and creating a once in a lifetime moment for everyone in attendance.

Taylor Swift and Carly Simon: You're So Vain.

Carly Simon - You're So Vain.

Carly Simon - You're So Vain ... Filmed for her 1987 Live From Martha's Vineyard concert.

Carly Simon You're So Vain.

Carly Simon official site "Who is You're So Vain About?"