If a singer has to transpose an entire role, we should at least ask whether he or she should be singing it. If you remember that Mozart’s keys were a whole step lower and Bellini’s and Donizetti’s about a half-step lower, however, there is certainly a case for transposition in my mind, particularly if the singer can bring in a wonderful performance. You are then left with the extra-artistic (i.e., business) considerations like the popularity of the singer with ticket-buyers and the expense of the copying work. (It can get pretty expensive to transpose an entire opera, but there are singers who will help cinch transpositions they prefer by bringing their own arrangements. It is worth their while to have them prepared and make them available.) So when a “double standard” is at work, it has some motivating business logic.

If a singer has to transpose only a particular passage, I am even more flexible. You have a great interpretation, terrific acting, and generally beautiful singing for more than 95 percent of the evening but difficulty negotiating a handful of notes? I wouldn’t hesitate to transpose the passage as long as the transition into the new key can be arranged smoothly. I’ll also give a singer a lot more latitude to transpose in a recital or concert. What I’m not interested in is taking an aria down in order to interpolate optional “higher” notes that the composer never wrote. That’s fraudulent in artistic and extra-artistic terms.

There certainly are transpositions that are more routine than others and some double-think going on. We transpose a lot of Rosina’s part up to use sopranos rather than mezzos in Barbiere di Siviglia, for example, and no one gives it a thought. But how is that different from any other transposition? A soprano (any soprano) can’t sing in the mezzo’s range all night; i.e., can’t sing what the composer had in mind. I have no objections to sopranos in the role. Some of my best friends are soprano-Rosinas; and one might question whether Rossini would even have written it for a mezzo if he had not had a star mezzo to write it for. But true purists should be objecting to this transposition as much as any other.