In his operas, Siegfried Wagner intentionally uses Sprachversagen [« failure of speech »] as a special means of expression. Speech is taken to the limits of its verbal ability, and then gives way to the music, which has to fulfil a rhetorical function. Music is thus used by Wagner in order to encode what he wants to say, the moments when Sprachversagen intervenes being key moments in the story.
This theory is illustrated by two examples drawn from the opera Schwarzschwanenreich.
