A lost duet between two rock legends is found.

FOX’s Lilian Woo reports:

For decades, few people knew it existed and no one knew where it was… Now a duet between Carly Simon and Mick Jagger, possibly from 1972, has turned up, apparently never heard in public…. Unlike her signature hit, on which the Rolling Stone contributed background vocals…

The buzz on fan websites is that it’s a slow love ballad believed to be named ‘Fragile’.

And Simon, in fact, mentioned the song in an interview with Rolling Stone Magazine two years ago, saying she and Jagger had a little back and forth at the piano for about an hour. The new discovery was found recently on a tape owned by Rolling Stones collector Matt Lee.

Lilian Woo, FOX News.

Follow Lilian Woo on Twitter: @LilianNY