"People can tell deeper truths and reveal more about themselves when they are in disguise," says composer Nico Muhly, whose new opera, Two Boys, embraces the operatic convention of "masked identity": but with a twist. Two Boys, which has its U.S. premiere at the Metropolitan Opera on October 21, uses the elements of a police drama to construct an opera narrative: a detective investigates the stabbing of one boy by another and is drawn into a complicated web of intrigue. Inspired by real-life events in England in the early 21st century, much of the opera is set in the digital world, as the boys at the center of the story communicate via Internet chat rooms.

"I'd like to think that it's both new and also very, very old," Muhly says of the story. "We don't live in a place where there are masked balls anymore. So I thought the Internet: where you can really pretend to be another person: would actually be quite a traditional frame for an opera."

Commissioned by the Met, Two Boys features a libretto by distinguished playwright Craig Lucas and is seen in a co-production with English National Opera (ENO), directed by Bartlett Sher (Il Barbiere di Siviglia, L'Elisir d'Amore). The two-act opera, which premiered at ENO in June 2011 when Muhly was only 29, was hailed by the New York Times as "a landmark in the career of an important artist... a work of dark beauty." Revised after the London run, Two Boys comes to New York with a new cast, conducted by David Robertson.

The idea of donning disguises is something common in Mozart operas, Muhly points out. In addition to CosÐ fan tutte, Le Nozze di Figaro, and Don Giovanni, the fast-talking composer mentions such operas as Handel's Partenope and Giulio Cesare and Rossini's Le Comte Ory. "Costumes are used for political and sexual reasons," he says. "What we're talking about is people using disguise and costume to tell each other dark, dark secrets or essential truths: a way of obscuring yourself to eventually say something more true.

"The standard operatic costume conventions have us, the audience, suspend disbelief: how could Dorabella and Fiordiligi not recognize their fianc_s in their ridiculous 'Albanian' costumes? On the Internet, it's much easier to actually get away with it: you can pretend to be anybody. You can change very subtle details about yourself (add a few years here, a few inches there) or change everything: your sex, your nationality..."

In the case of Two Boys, the mystery centers on the relationship between two young teenagers that unfolds on the Internet, a place that Muhly finds full of "allure" and "insane longing." Muhly grew up in tandem with the rise of the Internet and the notion of an opera set within the shadowy world of the web resonated with his own experience. When he first discussed the idea with Lucas, Muhly was pleased that the playwright shared his interest in how the Internet affects modern life.

This was Muhly's first large-scale opera (he simultaneously wrote his chamber opera, Dark Sisters, a story about a polygacourtesy the artist mous American religious sect, which premiered in the fall of 2012). Once he and Lucas set to work, the writing moved very quickly. Two Boys takes the shape of a police drama, with Detective Anne Strawson, played by mezzo-soprano Alice Coote, as its "governing force." "She's a creature of the analog world," says Muhly, who explains that, in this story set in the early days of the Internet, the detective doesn't even own a computer. "She's used to evidence being presented in a certain way. That needed to be someone with a weight and a serious sort of melancholy of her years behind her voice."

Tenor Paul Appleby takes on the role of Brian, a 16-year-old boy who is manipulated through a series of chat room interactions into stabbing a younger teenage boy, the 13-year-old Jake. To unravel the crime, Detective Strawson pores over chat room transcripts and interrogates the naive Brian. He tells a convoluted and seemingly impossible tale in which a host of colorful personalities of disparate ages: from a teenage temptress to a malevolent gardener: all swirl around him. Faced with this foreign online world, the detective struggles to figure out what is real and not real.

In the offline world of the police station, the musical language is lyrical, following the rhythm of conversation, and at times, interrogation. There are set arias with haunting language, such as these lines from an aria for Detective Strawson: "How does he do it/this infinite spool of lies...? From which god does he take such dictation/What talent is this?/What gift?/ Am I struck dumb by the marvel? Could I speak in such tongues?" Like Brian's parents, she is bewildered by the world the children find so intoxicating. "They've killed off beauty," she sings. "Ghosts in machines... that's all they have."

Sher notes that Muhly "finds complexity in the sound of young people's innocence: it's a deep exploration of innocence, sexuality, personality, and expressiveness between people in this new medium." And the musical evocation of this watery world of the Internet, buzzing with simultaneous conversations and multiple chat rooms, is startling. "I began to explore this language of what it sounds like when the entirety of a chorus has one core but all these different pieces of text they can sing at different times," Muhly explains. "So it's controlled, but it's shimmering from inside. It should sound like that magical thing that happens when birds all move at the same time and cluster with each other, or schools of fish or any massed group of little things. There's a finite architecture to the music, but there's an infinite depth because no one's singing the same thing at the same time."

He says he has been experimenting with "gigantic breathing choral textures" for several years. "The choral music in Two Boys also references the ecstatic vocal music of Meredith Monk and Steve Reich's use of vocal canons: the sense of overlapping vocal patterns creating a larger architecture of meaning. It's almost as if you're hearing the entire aggregate of all the things that people are saying on the Internet at once."

In the six choruses that evoke the online world, Muhly used unusual notations in order to create vivid musical effects. In one instance, the "text" for a sustained note extending over many musical bars is "[phone numbers]". Muhly gives this instruction: "Each singer should randomly sing, on the given pitches, any phone number that comes to mind. The result will be a wild chattering."

Since the story shifts time and place in the blink of an eye and occupies both reality and the hyper-reality of cyberspace, the production was conceived to address those demands. "There are almost no spatial transitions," says Muhly, "with the exception of one incredible 'moment,' which lasts almost 20 minutes. Craig and I were constantly challenging Bart to make the space one in constant transformation. Once it was clear that the music required that, all the design fell into place."

Sher describes the set, designed by Michael Yeargan, as "a system of moving towers that are all projection surfaces and also large edifices that can transform into many kinds of spaces. It's a space of the imagination and of projection and it's a private weird corner of your existence. You are really just creating a layered space in which many, many things are happening at once, in the same way we can open every window in a house, or on a computer, and simultaneously feel like we are in many places all at the same time."

In addition, the striking video projection and animations designed by 59 Productions can instantaneously conjure a wide variety of settings and dramatic visual landscapes. They bring to life the visual world of the Internet, from projected chat room text and thumbnail photos of its inhabitants, to a depiction of the Internet itself using cascades of abstract, emotionally charged imagery.

The lighting is by Donald Holder and the costumes are by Catherine Zuber, whose choices reflect the setting of 2001, when the action takes place. Following the premiere run at ENO, choreographer Hofesh Shechter has joined the production team, creating a layer that Muhly describes as "subtle choreography that occasionally explodes."

The opera is the first Met production to come out of the Metropolitan Opera/Lincoln Center Theater Opera/ Music Theater Commissions Program. The performances follow four workshops, both before and after the ENO premiere, the last of which took place in the fall of 2012. Muhly said he and Lucas welcomed the chance to figure out how best to "keep the shark always in motion," addressing structure and pacing issues, rebalancing material in the two acts, and creating a more focused ending. "I come from a generation where operatic proportion was equally informed by bel canto and by Wagner, as well as these large experimental minimalist works like [Philip Glass's] Einstein on the Beach and Satyagraha. So I was obsessed with the idea of being able to workshop the piece and to hear some version of it from beginning to end a bunch of times."

Sher says the workshops allowed the team to be able to delve into "the central character of the detective, and into the relationship between the boys and what the core of that is, and uncovering slowly how to deepen those experiences." As a result, the audience is given a window into the detective's melancholy personal life, as well as more insight behind what motivated the bizarre online masquerade.

At the end of the day, this opera culled from what Sher calls "the early, Wild West days of the Internet," tells a haunting and deeply human story. Though set in a digital fantasy space that has only emerged in recent years, its themes are timeless. "There's this sense of longing that pervades all these interactions online, and the sense that, if you're lying to someone or being lied to, does that matter if you're hearing what you want to hear?" asks Muhly. "It's a contemporary take on a very, very traditional story of what people do in the face of loneliness, at a cost to themselves, to make connections with other people."