Susanna, a Neopolitan countess of the early 1800s, has a segreto, a secret: she smokes. Her husband, Count Gil, an obsessively jealous man — but a perfectly nice fellow in every other way — sniffs tobacco in the palace and draws a logical but preposterous conclusion: Susanna is having an affair with a man who smokes. The pair is at loggerheads, and more than willing to sing about it, courtesy of the great Enrico Wolf-Ferrari. Thus unravels the 15-minute intermezzo comic opera, Il Segretto di Susanna, to the merriment of all.

This weekend The Yard in Chilmark brings opera to its famous barn theatre, and not just any old opera, but the ultra engaging opera buffa, begun in Naples with a big push from Alessandro Scarlatti in the late 1600s, and played out in subsequent centuries to the tunes of Bizet and Offenbach in France, Beethoven and Strauss in Germany, Zarzuela in Spain, and Gilbert and Sullivan in England. The Yard is calling its event, aptly enough, Jealousy, Deceit, Love, Laughter.

Comic opera has at its core a plot that is pure farce. Misunderstandings flourish, doors fly open and slam shut, ingenues faint, flutter and pout, good guys rush, tilt and dodge, and bad guys skulk and attack. Characters are welcome (as they say on the USA channel) only insofar as they fit a generic mold: composers were known to raid their own earlier works for standard-issue lovers, go-betweens, and heavies.

On Tuesday the Gazette caught up with Yard rehearsals. Conductor Elizabeth Scott from New York, with short dark hair, tall and lanky with the metabolism to go, enthused about the program (in addition to Segretto, The Yard will present the first act of Gioachino Rossini’s masterpiece, L’Italiana in Algeri): “There’s this madcap finale in L’Italiana where all seven cast members — pirates and everyone — sing as loud and fast as they can, all at the same time. We’re doing it in Italian because it carries the type of patter we love from Gilbert and Sullivan, but we’re having a comic duo on stage to translate the action.”

Ms. Scott, who works with the Bronx Opera and American Opera Projects, and who recently received the prestigious award, the Bruno Walter, said bringing light opera to Chilmark was the idea of Yard artistic director and choreographer (and, it turns out, well-versed opera director and devotee) Wendy Taucher. “Wendy held full-fledged auditions in New York, and I was brought in after the casting was finished. But opera is such a small world, I already knew, and had worked with, almost everyone.”

Back in the barn, the trio of performers for Il Segreto, Justin Ryan, Nicole Lee Aiossa and Mitch Tebo assembled, the latter two barefoot, but all three dressed in early 19th century European costumes (think Napoleon and Josephine). The pianist, Samuel Kardos, clad in early 21st century attire of jeans and orange T-shirt, announced he needed more light for his pages of music. Ms. Scott rummaged around until she found a lamp which she brought over to the piano and plugged into a wall socket. A curiously familiar-looking red-headed woman seated in the second row perched with a three-ring binder of music in her lap.

Introductions were made as Ms. Taucher announced, “We’re lucky to have Marni Nixon helping us with vocal coaching.” Marni Nixon, as in the TV and Broadway star, and the singing voice of Natalie Wood in West Side Story, Audrey Hepburn in My Fair Lady, and Deborah Kerr in The King And I? The very one. Ms. Nixon is also scheduled to perform this Sunday, August 17, at 3 p.m. in a special event, The Yard At The Tabernacle, with Katie Mayhew and Abigail Southard, two young Vineyard singers in line to fill the shoes of Lillian Norton, a.k.a. Madame Nordica of earlier Island songstress fame.

In a seat down front, Ms. Scott lifted her pencil-thin baton, and the pianist began to play. Mr. Ryan materialized center stage and sang in a rich baritone, “’My eyes may deceive me, but not my nostrils! Who dares to smoke in my palace?’” Taucher, stationed several rows up from the conductor, said, “Justin, can you give us more defined motions on the sniffing?” She demonstrated. The singer sang and sniffed more pronouncedly. Much funnier.

Ms. Aiossa joined the action, her bewitching soprano voice braiding with her partner’s deep one. Mr. Tebo as the pantomiming footman, brought tea and sight gags to the action. At one point Ms. Nixon inserted a musical critique: “Can you make it softer here? It says ‘pianissimo’ all through this section.” The singers nodded. Ms. Taucher, too, had a suggestion: “Why don’t you two guys take off your heavy jackets? Might as well rehearse in comfort.”

Mr. Ryan removed his heavy brocade coat, exchanging it for a vest. “I don’t look too much like Darcy in Pride And Prejudice, do I?” Some moments later Ms. Taucher stopped Mr. Ryan to compliment him on a comically lavish gesture cum vocals. “Very Placido,” she said.

“That’s good?” he asked.

“It’s good in this case.”

During breaks Ms. Aiossa and Mr. Ryan horsed around. At one point the soprano moved ethereally across the stage sipping from a bottle of Dasani water.

A little later, Mr. Ryan strode downstage and, as he sang, executed a spin, a gavotte and a kick to emphasize his exploding passions.

After watching the combination several times, Ms. Taucher asked Ms. Scott, “Is there a retard here?”

Ms. Scott nodded eagerly. “Yes. It’s very Mozart.”

As the rehearsal block for Segreto wound down, the cast for L’Italiana trickled in. Ms. Taucher had to leave for a board meeting taking place in one of the many glens dotting the grounds. Before she could get away, she was surrounded by people in need of feedback: Liz Villard on board for lighting, board member Charlotte Hall, and assistant Lise Brody. A quarter of an hour later in the barn, a cast of seven sat on stage in a half-circle of red folding chairs. With Ms. Taucher temporarily absent, the rehearsal was all about the music. Ms. Scott alternately talked and sang her directions. The cast members stood as their parts were cued. Ms. Scott told them, “It’s secco here, so keep it dry but give it emphasis when you need it,” and then she demonstrated with several bars of song.

Come opening night, a violinist will be added to the mix, but for now, when three or more of the L’Italiana voices chimed in, the sounds filled every molecule of the barn, and the result was nothing short of magnifico.

The family show The Yard at the Tabernacle — comic music and dance by Island kids and Yard artists, including Marni Nixon and Katie Mayhew — is Sunday, August 17, at 3 p.m. at The Tabernacle in Oak Bluffs. Tickets are $5 general admission and $20 premium seating.

Jealousy, Deceit, Love, Laughter: Opera at The Yard is on Friday, Saturday and Sunday, August 15 to 17, at 8 p.m. at The Yard. Free pre-concert talks by Cori Ellison, dramaturg of New York City Opera begin at 7 p.m. Tickets range from $15 to $100 (for the opening night benefit premium seating and dessert reception). For details and tickets, call 508-645-9662.