Her topmost register is unusually lucid and effortless. Even in those notes unattainable by most other sopranos, and even when those notes are held far longer than the pecks requested by most other composers, Ms. Luna’s tone is full. She manages to avoid shrillness in what she aptly calls the “Wagnerian coloratura spectacle” that is her final “Exterminating Angel” aria, a flood of sustained superhigh sound up to F.

Even if nothing in previous Met history has equaled her high A, other singers have come close, sometimes adding unwritten interpolations and transpositions to show off their personal stratospheres. A number of the highest notes in Met history have emerged from sopranos singing the title part in “Lucia di Lammermoor”; it’s no coincidence that this is the role Ms. Luna’s character performs just before the dinner party at the start of “The Exterminating Angel.”

Ellen Beach Yaw, born near Buffalo in 1869, sang a G above C as Lucia in her single Met performance in 1908. The review in The New York Times praised her “flutelike Santos-Dumont notes,” comparing her to a Brazilian aviation pioneer, and added, in a reference to a Wild West gunslinger: “She hit that high G as promised, but it is like Bat Masterson hitting a tomato can with a .44 at four paces.”