Christopher Hogwood laments the casual way opera directors edit and disfigure operas. “The great liberties taken in opera productions today are often laughable and ludicrous: think of Brünnhilde with her head in a paper bag or cleaning her teeth while Siegfried is declaiming his love, or of the chorus in Verdi’s Un Ballo in Maschera sitting on toilets. But such silliness is, strictly speaking, cosmetic: close your eyes and the music proceeds as intended, and eventually she removes the paper bag and they pull up their trousers. But amputate an aria, remove a recitative, reallocate an interval and, even with eyes closed, the structure wobbles fatally.”