Fidelio is an interesting piece. The music is great and it has a powerful, very straightforward, plot. There are no convoluted subplots here. But there is a lot of spoken dialogue which slows things down. Is it necessary? Claus Guth doesn’t think so and in his 2015 Salzburg production he replaces the dialogue with ambient noise and also doubles up Leonora and Don Pizarro with silent actor “shadows”; the former using sign language in the manner of the narrator character in Guth’s Messiah. It works remarkably well. The ambient noise sections are quite disturbing and the “shadows” add some depth, especially the frantic signing in the final scene. Perhaps worth noting that the “noise” contains a lot of very low bass and precise spatial location. It may need a pretty good sound system to have the intended effect.