To most opera lovers, it’s as familiar as their own hands: the opera about an opera singer, Giacomo Puccini’s “Tosca.” To newcomers, it can seem the epitome of the heightened emotions and tragedy that are stereotypical of opera. And to musicians like those in Washington National Opera’s upcoming run of the opera, from May 11 to 25, “Tosca” represents a set of challenges that the audience may not even have considered.

“I’m trying to find the diva in her,” says Keri Alkema, one of the two sopranos who will share the title role. “Nowadays, it’s been beaten into me: Don’t be a diva. All of a sudden, I’m told I get to unleash her. That’s a little scary. Do I want to let her out?”

“Tosca” is the story of a soprano who’s in love with a painter named Cavaradossi in 19th-century Rome, a city ruled by the evil Baron Scarpia. Scarpia arrests Cavaradossi and offers Tosca a trade — her sexual favors for her lover’s life — but Tosca manages to kill Scarpia before his desire is consummated.

The piece is eminently theatrical. Gone, by Puccini’s day, were the conventions of Italian bel canto opera, with its arias (slower songs) followed by cabalettas (faster ones). Puccini’s music, written in the style known as verismo (realistic), is more fluid and through-composed, though it certainly pauses for big moments, such as Scarpia’s blasphemous “Te Deum” in the first act (“Tosca, you make me forget God!” he sings) and Cavaradossi’s anguished memories of Tosca, “E lucevan le stelle” (the stars were shining), as he awaits execution in Act III.

“Puccini is such a theater man,” says Speranza Scappucci, the Italian conductor who leads this production. “Nothing, nothing in the score is left to chance.” She adds: “The risk with Puccini is that we get very Romantic and gooey in the beautiful melodies. You don’t have to add sugar; it’s there.” In other words: Rather than wallowing in the lovely music when you sing or play it, “everything that is action, that is dialogue, needs an urgency,” she says, to communicate the drama.

Tosca’s signature moment, and the audience’s favorite, is the aria “Vissi d’arte,” the singer’s heartfelt plea to God as she and Scarpia prepare for their final confrontation. Inconveniently for the soprano, the aria, which requires pinpoint control and a lot of floating pianissimo singing, comes at the end of an impassioned scene with Scarpia that involves a lot of yelling. “You’re hyperventilating; he’s just attacked me,” says Alkema. “Right before ‘Vissi d’arte,’ there’s about eight measures” in which the military drums are heard outside. “That’s the moment to calm down, get the breath underneath you.”

“To get your heart rate down is damn near impossible,” says Latonia Moore, who is making her company debut as the other Tosca. “It’s about letting your body go all the way down to almost nothingness. A lot of people [ask], how could he put an aria like this in the middle of everything when you’re so exhausted. [But] that’s the point. That’s the feeling you have to give the audience: You’re so exhausted you can’t sing any more.”

Moore and Alkema are coming at Tosca from different directions — though both singers, notably, started their careers as mezzo-sopranos. (Alkema was in WNO’s inaugural group of Domingo-Cafritz young artists.) When she started trying out Puccini, Alkema wondered if her voice would be big enough to carry over the orchestra; Moore, by contrast, frequently sings the heavier role of Verdi’s Aida (though she points out that in contrast to some of Aida’s quieter passages, “Tosca is full throttle all the time.”)

For Moore, who has done the role of Tosca only twice before, the biggest concern about the part are its high Cs — six of them, most in the dramatic second act. “I’m not going to lie,” she says, “they scare me. People are waiting for those high Cs, and I’m crossing my fingers and praying to God.”

High Cs are a benchmark for everyone and come easier to some singers than to others. Alkema noticed that an acting tip from the production’s director, Ethan McSweeny, applied to singing as well. “The director was explaining to us that if an acting moment doesn’t work, it’s never that specific moment” that’s the problem, she says. By the same token, “It’s not the high C that didn’t work; it’s everything leading up to it. You have to go back four or eight measures [to work out] what went wrong. I can pop out a high C right now, but it won’t go the same way if I ride up with an orchestra.”

“Tosca” isn’t a heavy sing for every singer. Alan Held, who sings Scarpia in this production, is a specialist in Wagner and Strauss (he sang Wotan in WNO’s “Ring” cycle in 2016). “What gets me is how short this opera is,” he says; the whole thing is shorter than a single act of some Wagner operas.

Yet Puccini’s style can be more difficult. “Wagner makes absolute sense,” Held says. “One thing is connected to the next, to the next, to the next. With Puccini, you have to jerk into another mind-set, vocally, from one minute to the next,” particularly in Act II, with all of its changes of mood and interruptions. Scarpia, like Tosca, has an aria that comes after all the loud singing, but it’s so short that many fans don’t even realize it’s there. “I don’t know anybody who brings that out for an audition,” Held says. “It’s not a showstopper.”

“Tosca’s” tricky rhythms and changing tempos challenge everyone — even in the orchestra pit. “Puccini’s always challenging,” Scappucci says, “because he changes meter and tempo in every bar. And if you try to be literal about it, it becomes very mechanical” — sounding like someone counting, rather than conveying the inner sense of the music.

Before getting to Washington, Scappucci spent hours poring over the score, looking not only at the notes but at the composer’s written indications in the margins of how the music is supposed to be played or sung. At one point in Act II, Scarpia is torturing Cavaradossi to find out where the political prisoner Angelotti is hiding, and Tosca, unable to bear it, reveals the hiding place. “Our Tosca was taking a lot of time to say, Nel pozzo del giardino [in the well in the garden],” Scappucci says. “But Puccini writes, ‘A tempo, con voce soffocata, rapidamente [in tempo, in a suffocated voice, rapidly].’ ” To demonstrate, Scappucci sings the orchestral chords leading up to the line, now infusing them with urgency, and then half-whispers Tosca’s line. “She doesn’t really want him [Cavaradossi] to hear it in the other room,” she points out. “It comes out of her without her even wanting to say it.”

Small details like this can help a whole scene come into focus. At the very end of the opera, Tosca, having witnessed Cavaradossi’s death, throws herself off the parapet of the Castel Sant’Angelo, while the orchestra plays the theme of “E lucevan le stelle,” traditionally slowing it down to linger over the tragedy. Yet the score marking is “con slancio,” meaning with a dash, leap, surge. “Figuratively, it’s her jump,” Scappucci says; so she plays it quickly and then slows down for the end, the landing.

Musicians in an opera orchestra have an odd experience of the work. They’re in the pit pouring their hearts out but often unable to see what happens on the stage. That’s why Karen Lowry-Tucker, a first violinist with the Washington National Opera Orchestra, goes to the Metropolitan Opera when she can. “Since I’m first violinist,” she says, “I’m along the wall [of the orchestra pit, and] I can see more than most. But it’s also a distraction,” she adds, “when you get too involved with the stage.”

Trained as an orchestral musician, Lowry-Tucker has had to adjust to an opera career — not least in that the performances are longer. “To me, opera is more challenging,” she says. “Not only do you have to learn your notes before you get to rehearsal but when you get there it’s not the way it was on the page. Andante [a moderate tempo] can turn to adagio [a slower one] if the singer wants. I have to depend so much more on a conductor in opera.”

“But I just love it,” she says, speaking of opera in general and of “Tosca” in particular. Of this opera, she says, “If you don’t love it, there’s something wrong with your heart.”

Tosca May 11-25 at the Kennedy Center, 2700 F St. NW. 202-467-4600.