Pardon Matthew Polenzani if his mind wanders ever so slightly midway through Act 1 of Bizet’s opera “Les Pecheurs de Perles (The Pearl Fishers).”

It’s during the entrance of Leila, the young priestess charged with protecting her Ceylonese fishing community from the perils of the sea. Polenzani is onstage watching -- but he’s also thinking about the aria that his character, Nadir, will soon be singing.

“I don’t mind admitting,” the tenor said in a telephone interview, “while we’re getting introduced to Leila and the chorus is hailing her arrival, it’s in my mind what I’m about to do.”

The aria is “Je crois entendre encore” (“I still believe I hear”), in which Nadir recalls, to a lilting barcarolle rhythm, his previous encounter with the beautiful maiden.

“It’s a dream because the music is so beautiful,” said the 47-year-old Polenzani, a mainstay at the Metropolitan Opera since his debut in 1997. “But it’s a nightmare, because it has to be sung quietly, and it’s really high. Plus the phrases are s-o-o-o long. There’s nothing else in the tenor repertory I think that’s even a little bit like it.”

Happily, he said, the required mixture of chest and head tones “plays to one of the strengths of my voice.” The opening-night critics agreed, with James Jorden in the New York Observer praising him for “floating out the lyrical aria in a seamless voix mixte crowned with a perfectly placed pianissimo high C.”

Audiences will get to see and hear him accomplish this feat Saturday afternoon when “The Pearl Fishers” is broadcast live in HD into movie theaters worldwide.

Even more famous than Nadir’s aria is the duet “Au fond du temple saint” (“At the back of the holy temple”), which he sings with Zurga, leader of the fishermen, who is portrayed in this production by baritone Mariusz Kwiecien. Before this season the Met had performed the entire opera only three times, in 1916, with Enrico Caruso as Nadir. But as an operatic excerpt, the duet has proved a hardy perennial, popping up on concert programs whenever both a tenor and baritone are in the lineup.

“The Pearl Fishers” has always been overshadowed by Bizet’s masterpiece, “Carmen.” Its music bears the stamp of a young composer of genius still finding his way, and the libretto is filled with improbable coincidences. In fact, as Polenzani noted, one of the librettists, Eugene Cormon, later said apologetically that “if we’d known how great the music was going to be, we’d have worked harder to bring it off in a better way.”

The role of Leila offers a glamorous showcase for a soprano, and Diana Damrau suggested the opera when Met general manager Peter Gelb asked her what she would like to sing with the company. “Yes, the story is a little trivial, and the surprises at the end are almost too much,” she told the New York Times. “But I choose this opera because I love it.’‘ The Met production, directed by Penny Woolcock, was first seen at the English National Opera and is conducted here by Gianandrea Noseda.

The Met’s HD broadcast will be shown starting at 1 p.m. EST on Saturday. A list of theaters can be found at the Met’s website: www.metopera.org/Season/In-Cinemas/Theater-Finder/ (AP)