“What I believe is that, according to the political context you’re in, you must be very aware of the references you’re using and how you present human suffering or human madness, whether it’s a tragedy or a comedic opera,” he said. “You must be very careful about whose side you’re on when you deal with characters in an opera. But you must also be very sure that you’re not turning your art form into a gourmet experience for vocal fudge-makers.”

“L’Italiana in Algeri,” considered one of Rossini’s first “mature” comic operas, was written when the Italian composer was 21 years old, in the early 19th century, and reflects certain cultural biases that were common at the time, Mr. Leiser said.

Earlier interpretations tended to stick close to the original libretto, which exhaustively mines the comic potential of cultural clashes. For the last 50 years, Mr. Leiser said, the traditional take was to portray the Arabs with long pointy shoes and big funny turbans, while the Italians were presented as elegant and dignified.

“The piece at its core, in a certain way, is a very Western take on Islamic culture, and normally Mustafa is portrayed as just stupid and ugly and the Italians are clever and very heroic,” Mr. Leiser said. “That was something I was not interested in at all. We had to find another story line to keep the genius of Rossini and the music and the libretto, and keep it as a real comedy, because it’s important to laugh. But comedy is serious business, and you must know what you are laughing about.”

Rather than altering the libretto, which Mr. Leiser said would be “cheating,” he engaged in many long conversations with Ms. Bartoli and Mr. Caurier to shift the interpretation. They decided to change Mustafa’s status from an Ottoman bey to a kind of local gangster who smuggles electronics at the port of modern-day Algiers, because they “felt that his behavior shouldn’t be generalized as Muslim behavior.”