You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "who sang backing vocals on you're so vain?" whose answer is Mick Jagger.
Each document should contain about 30 words, and these documents should contain useful information.

Query: backing vocals on you're so vain
Useful Output:

Doc 1: One of American singer, songwriter and children's author Carly Simon's most popular hits is “You're So Vain,” which she wrote in 1971 and recorded the
Doc 2: Uncredited, hear Rolling Stone's Mick Jagger sing backing vocals on Carly Simon's number one single, You're So Vain.
Doc 3: Mick Jagger sang the instantly identifiable backing vocal. Throughout the years Simon has refused to say publicly who exactly “You're So Vain”
Doc 4: You're So Vain - Carly Simon Story Behind The Song. 15K views  Carly Simon - Mick Jagger sang backup on You're So Vain. Carly Simon
Doc 5: In 1972, Carly Simon invited Mick Jagger to the studio. She was recording "You're So Vain" and Jagger provided backup, uncredited.