What’s So Bad About Peter Seiffert’s Earpiece?

The tenor is singing Wagner’s Tristan for the first time at the Met, and many opera lovers are tut-tutting at his use of an electronic earpiece to get cues from a prompter. “It has long been standard practice for an operatic artist who has prepared a role thoroughly to take cues from a house prompter. But does a singer cross a line by putting an electronic gizmo in his ear?”