If it works once

In John Ford’s YOUNG MR. LINCOLN (1939), starring Henry Fonda, Abe's boyhood sweetheart Ann Rutledge is accompanied on-screen by a lovely musical theme, which reprises when Lincoln thinks about her years after after her early death. Twenty-three years later, Ford used the exact same melody in THE MAN WHO SHOT LIBERTY VALANCE (1962) when Hallie (Vera Miles) reminiscences about the love of her youth, the now deceased Tom Doniphon (John Wayne). Hallie and Tom, like Ann and Abe, never consumated their relationship in marriage.