It lasts just a split second, almost imperceptible in a two-hour score. It’s over too quickly to summon the dogs of the Upper West Side or to break any nearby windows.
But brief as it is, the A above high C that the soprano Audrey Luna reaches in Thomas Adès’s new opera, “The Exterminating Angel,” is so high, it has never been sung in the 137-year history of the Metropolitan Opera.
But a high A — a combination of genetic gifts, rigorous training and psychological discipline over two fragile vocal cords — is monumental, and unprecedented at the Met, according to its archivists.
“There’s a particular thrill about that high coloratura range,” Mr. Adès said in a phone interview. “When I hear the conventional high C of a soprano, I want to say, ‘Show us what else you’ve got.’”