Mary McCartney has directed a new documentary "If These Walls Could Sing" that chronicles one of the most famous and historic recording studios in the world: Abbey Road. As a baby, Mary was crawling around on the floor while her dad Paul was laying down tracks at Abbey Road and she has the footage to prove it. In addition to Paul McCartney, the film features interviews with Elton John, Jimmy Page, and Roger Waters. "If These Walls Could Sing" premieres on Disney+ on December 16.