 Although it shared its name, the song was not intentionally made for the 2009 concert documentary Michael Jackson's This Is It. "This Is It" was written by recording artists Paul Anka and Michael Jackson, and a demo version of the song was recorded by Anka and Jackson in 1983 at Anka's California recording studio. The song was intended to be added as an album track on Anka's 1983 duets album Walk a Fine Line that he was in the process of recording at the time. Anka claimed in 2009 that following the release of Jackson's 1982 album Thriller, Jackson "stole the [master] tapes" from Anka's recording studio.
