Richard Wagner -

He pioneered the use of "musical nametags"—short, recurring musical phrases associated with specific characters, objects, or themes.

Richard Wagner (1813–1883) was a German composer, conductor, and theorist who fundamentally altered the course of Western music. He is best known for his monumental operas, which he preferred to call and for his revolutionary concept of the Gesamtkunstwerk (total work of art). Artistic Philosophy and Innovations richard wagner

Wagner even had a theater specially built in Bayreuth, Germany, to accommodate his massive productions and specific acoustic requirements. The Life of Richard Wagner: Operas, Music & More - ENO Music & More - ENO