Four uninvited guests, disguised in masks, have snuck into the party. It’s Roméo of the Montagues and his pals: Mercutio, Benvolio, and Stéphano. Roméo tells them he’s had a strange dream. Mercutio says it’s probably a fantasy sent by Queen Mab, the fairy queen. Roméo spots lovely Juliette across the crowded room and immediately falls in love.

Juliette tells her nurse Gertrude that she has no interest in marriage, spelling out her feelings in a carefree aria. Roméo approaches and begins some charming banter. Juliette is beguiled and sings along. Just at the moment they discover each other’s identities, Tybalt recognizes arch enemy Roméo and vows to kill him. Roméo hustles off and Lord Capulet once again urges the guests to dance the evening away.

Act II

Later that night, Roméo creeps into the Capulet garden. Juliette steps from her room onto her balcony and Roméo declares his love, comparing Juliette’s beauty to the rising sun. Capulet courtiers come looking for Roméo, he hides, they go away, and Juliette responds from the balcony with her pledge of love. The youngsters vow to marry.

Act III (Scene 1)

Roméo realizes there’s only one person to whom he can safely confess his love for Juliette — the wise and beloved Frère Laurent. Laurent is alarmed when Roméo explains his dilemma but when Juliette and Gertrude arrive and the couple asks to be married, he agrees and weds them, thinking this could be a way to reconcile the feuding families.

Act III (Scene 2)

Outside the Capulet palace, Roméo’s friend Stéphano sings a deliberately taunting song about a poor turtle dove captured by vultures. A Capulet servant is insulted, Mercutio tries to protect Stéphano, and, after a sword fight, Tybalt kills Mercutio. Roméo, outraged by his friend’s death, kills Tybalt. The law arrives in the person of the Duke of Verona. After hearing appeals from both sides, he declares Roméo innocent of murder but says he must still face punishment — immediate exile from Verona. Roméo vows to ignore the order so he can spend the night with his bride before leaving the city.

Act IV

The newlyweds awake after their wedding night and Juliette forgives Roméo for killing Tybalt. They pledge everlasting love and Roméo departs. Lord Capulet arrives and announces to his daughter that she is to marry Count Pâris that very day.

Juliette cries out to Frère Laurent in desperation. He gives her a special potion that will make her appear dead but for only a day. He explains that Roméo will be at her side when she awakes. Juliette summons all her courage and drinks the potion. She collapses on the way to the wedding ceremony and, to the horror of all, is pronounced dead.

Act V

Juliette is laid on a bier in the Capulet’s family crypt. Roméo never received Laurent’s explanation of the fake death. Roméo arrives, discovers Juliette’s body, and believes her to be dead.

He is shattered and drinks actual poison. Juliette wakes from her temporary coma and the two sing of their hoped for future. Roméo falters as the poison takes effect. Juliette, aware of what’s happening, plunges a dagger into her body. Praying for forgiveness, the two ill-fated lovers die in each other’s arms.

- Performance notes by Eugene Carlson

He became seriously religious, considered becoming a priest later in life and began seminary studies but the composing life won out, especially sacred music that flowed from his devotion to the Renaissance composer Giovanni Pierluigi da Palestrina. Gounod wrote 21 masses, dozens of songs, both religious and popular, and the frequently performed St. Cecilia Mass, where in the words of composer Camille Saint-Saëns, the music’s “simplicity, grandeur and serene light rose above the musical world like the dawn.”

To escape fallout from the Franco-Prussian War, he moved his family from Paris to London in 1870, became the first conductor of the Royal Choral Society, and wrote three oratorios. He also composed a well known Ave Maria where the melody is superimposed over the C major prelude of The Well-Tempered Clavier that J.S. Bach composed 137 years earlier.

On the secular side, Gounod wrote two symphonies that failed to ignite much interest. His track record with opera started slowly with Sappho in 1851. Eight years later, at age 41, he hit his career jackpot with Faust, based on the Goethe tragedy that he first read during his Rome residency two decades previously.

After a cautious debut, Faust took off and became a box office winner wherever it played. It’s the Metropolitan Opera’s eighth most-produced production. Gounod’s melodic gifts are on full display in Marguerite’s “Jewel Song,” the stirring “Soldier’s Chorus” and Valentin’s poignant baritone aria, “Avant de quitter ces lieux.” So celebrated was Faust over Gounod’s previous work that one critic caustically suggested it must have been composed by someone else. A livid Gounod challenged the critic to a duel and the critic backed down.

Of Gounod’s 13 operas, only Faust and Roméo et Juliette, his ninth opera, achieved lasting popularity. In America, his “Funeral March of a Marionette” is forever linked with Alfred Hitchcock as the theme song of Hitchcock’s television mystery series.

Gounod was revered in his time and his musical output was immense but his reputation lost ground to a mania for the music of Richard Wagner that swept Europe in the late 1800s. Out of date and a bit stodgy, was the popular verdict. He died of a stroke at age 75 at his home in Saint-Cloud, a Paris suburb. Saint-Saëns, played the organ at Gounod’s funeral and the composer Claude Debussy summed up the composer’s career: “The art of Gounod represents a moment in French sensibility. Whether one wants to or not, that kind of thing is not forgotten.”

- Performance notes by Eugene Carlson

Roméo et Juliette followed Gounod’s other opera hit, Faust, by eight years. It was a shrewd marketing move by Gounod, since opera was far more profitable than Gounod’s speciality, sacred music. The Shakespeare opera was an instant hit and marked the high-water mark of the composer’s popularity and influence.

The opera follows the Shakespeare story with a few exceptions. Several characters from the play are deleted and a new character is added: Stéphano, a pal of the Montagues. It’s a “trouser role,” a male part sung by a woman. Midway through Act I, Juliette is given a high-spirited aria, “Je veux vivre,” a coloratura show-stopping waltz in which Juliette says she wants to have fun for a while and not worry about marriage. An out-of-character attitude for Shakespeare’s Juliet.

Most jarring, the teenagers’ double suicide at the end of Shakespeare’s play serves to reconcile the Montagues and Capulets and end their long-standing feud. The opera makes no such concession. Gounod’s finale is brutal and tragic in the true sense of the word. The children are crushed by a patriarchal society. With feuding families, hard-hearted parents and social institutions allied against them, the only way the young married couple can ultimately be together is as two dead bodies in a tomb.

Gounod’s marvelous score is just one highlight after another. Four brilliant duets between Roméo and Juliette frame the story. Add to that the unusual choral prelude that Gounod cribbed from the Berlioz symphony, Mercutio’s jolly “Queen Mab aria,” and the quartet with the two youngsters, Frère Laurent and Gertrude, Juliette’s nurse.

To wrap it up, in vivid contrast to her happy-go-lucky aria in Act I, Juliette sings a stunning soliloquy as the climax nears, in which she considers the coma-inducing drug she’s about to drink. Will it work? Is this what I should be doing?

The Poison Aria, “Amour, ranime mon courage,” or “Love revive my courage,” is a tour de force. Musically, it’s so demanding and requires so much stamina from the soprano, coming near the end of the show, that music directors occasionally take pity on the Juliette character and cut the aria from the performance.

In a recent episode of the podcast Aria Code, soprano Diana Damrau recalled the excruciating dilemma Juliette faces in this conversation with herself. “The journey. The desperation. Oh, my God! Is this right what I’m doing? She has this poison in her hands. The music bursts out. It’s heaven and hell in the same moment.”

Damrau adds: “In the end, she kicks away all the fear, all the bad things, because she knows she has to do this.” It’s the opera distilled in six thrilling minutes. “This music that Gounod gives us. It’s medicine for our souls,” Damrau says. “It gives us so much.”

- Performance notes by Eugene Carlson