A leitmotiv (líte-moh-teef) — guiding, or leading, motive — is a musical motive associated with some person, thing, idea, or symbol in the drama. By presenting and developing leitmotivs, Wagner’s orchestra guides the listener through the story.

Leitmotivs are easy to ridicule when they are used mechanically — when, for example, the orchestra obligingly sounds the Sword motive every time the hero reaches for his weapon. On the other hand, leitmotivs can suggest with considerable subtlety what the hero is thinking or feeling even when he is saying something else — or saying nothing. Wagner also became very skillful in thematic transformation, the characteristic variation-like technique of the Romantic composers (see page 232). By transforming the appropriate motives, he could show a person or an idea developing and changing under the impact of dramatic action.

And since, for the Romantics, music was the undisputed language of emotion, leitmotivs — being music — could state or suggest ideas in emotional terms, over and above the intellectual terms provided by mere words. This was Wagner’s theory, a logical outcome of Romantic doctrine about music. Furthermore, the complex web of leitmotivs provided his long music dramas with the thematic unity that Romantic composers sought. On both counts, psychological and technical, leitmotivs were guaranteed to impress audiences of the nineteenth century.