Who contributed uncredited backing vocals for the song “You’re So Vain”?

"You're So Vain" is a song written in 1971 by Carly Simon and released in November 1972. It is one of the songs that Simon is most identified with, and upon its release, reached number 1 in the United States, Canada, Australia, and New Zealand. The song is ranked at number 92 on Billboard's Greatest Songs of All-Time. In August 2014, the UK's Official Charts Company crowned it the ultimate song of the 1970s.

Mick Jagger contributed uncredited backing vocals for the song. When asked how this collaboration occurred, Simon said: "He happened to call at the studio. … I said 'We’re doing some backup vocals on a song of mine, why don’t you come down and sing with us?'"

Sir Michael Philip Jagger (born 26 July 1943) is an English singer, songwriter, actor, and film producer who gained worldwide fame as the lead singer and one of the founder members of the Rolling Stones. Jagger's career has spanned over five decades, and he has been described as "one of the most popular and influential frontmen in the history of rock & roll". His distinctive voice and energetic live performances, along with Keith Richards' guitar style, have been the trademark of the Rolling Stones throughout the band's career.