leitmotif (n.)

also leitmotiv, "a musical figure to which some definite meaning is attached," 1876, from German Leitmotiv, literally "leading motive," from leiten "to lead" (see lead (v.1)) + Motiv (see motive). A term associated with Wagnerian musical drama, though the thing itself is at least as old as Mozart. "The leitmotif must be characteristic of the person or thing it is intended to represent." ["Elson's Music Dictionary"]