The first image in the poignant, propulsive new E.D.M.-pop musical “The Heart,” at the Roundabout’s Laura Pels Theatre, is of a young surfer, Simon (Nick T. Daly), swaying in solitary bliss, like the only dancer left at a club. Behind him, a neon line pulses—it’s an ocean swell, an electrocardiogram, a musical beat. Just nineteen, Simon has slipped out early to catch a predawn wave, but on the drive home he’ll be critically injured in a crash.

And, in a flash, Simon is no longer the show’s protagonist—instead, his heart is. As bright grids fill up screens that frame the stage, the musical—smartly directed by the Roundabout’s new artistic director, Christopher Ashley, with lighting by Amanda Zieve, immersive video design by Lucy Mackinnon, and subtly gliding choreography by Mandy Moore (the auteur behind Taylor Swift’s Eras Tour)—becomes a thrilling, thrumming twenty-four-hour countdown to an organ transplant, tracing the path from one person’s tragedy to another’s miracle. We meet Simon’s powerhouse mother, Marianne (a moving Joaquina Kalukango, belting in denial by her son’s bedside); her prickly ex-husband, Sean (Jason Tam); Simon’s girlfriend, a d.j. named Juliette (Max McKenna); and also the medical team, including a warm, no-filter nurse (a fab Bre Jackson) and a cocksure surgeon (Drew Gehling, who, after playing doctors in “Waitress” and “Little Shop of Horrors,” may qualify for a medical degree). Later, we meet the recipient of Simon’s heart, portrayed with rueful glamour by Heidi Blickenstaff. These characters are distinct individuals, but there’s a fungibility to the whole enterprise: we meet each of them briefly but intensely, in passing, the way you do in a hospital. The cast juggles minor roles, so a patient might reappear as a doctor; Simon’s surfboard becomes an operating table.

The central concept, adapted by Kait Kerrigan from a poetic French novel, could easily go gooey or gimmicky, like a musical episode of “Grey’s Anatomy.” At first, there’s an almost bludgeoning pathos to what we witness, as Marianne resists the news that her son—brain-dead, but still with a beating heart—is gone. But, just as her grief becomes unbearable, a jarring image intervenes. At center stage, a fey stranger appears, warbling in a high operatic voice, with bright-blue gel patches under his eyes and a white towel wrapped around his head, diva style. Only after his phone rings do we learn who this person is: Thomas (Lincoln Klauss), the hospital professional assigned to persuade Marianne and Sean to donate Simon’s organs. “They might be divorced?” a colleague tells Thomas, filling him in on the case. “The divorce’ll be fun,” he responds, tartly.

It’s a tonic splash of detachment before Thomas’s mask of professionalism slides back up. Some of the production’s strongest moments feature this sort of tricky tonal pivot, as when a punkish gamer (a terrific Wren Rivera) is unveiled as the gleeful consultant who selects organ recipients using an algorithm. The show’s lyrics are often literal-minded, with rare outliers, such as a wry joke about Juliette becoming “a side piece to his nine-foot slab of fibreglass.” But did that blunt sincerity deliver emotionally? It sure did. Before long, my eyes stung; my chest got tight. If the critical part of my brain sometimes resisted an obvious turn of phrase—“You are my heartbeat,” say—the rest of my body was all in.

There was certainly no resisting the score, an audacious suite of electronic anthems and ballads co-written, with some help from Kerrigan, by the married pop-music wizards Anne and Ian Eisendrath, the latter of whom was an executive music producer for the banger-heavy “KPop Demon Hunters.” Broadway musicals have mined everything from rock and pop to hip-hop and folk. But there’s something bracingly logical about injecting the synthetic jolt of electronic dance music into a hospital environment, where vulnerable bodies are sustained by machines. The score has an exhilarating artificiality, from the breakneck “Keep Up,” which is punctuated by the beeps of hospital monitors, to the kinetic “Strike the Match,” in which layers of slick digital uplift thicken like shellac as the consultant homes in on her match. Any rhythm that repeats becomes fodder—the whoosh of the ocean, the boop-boop of video games. It’s an aural vocabulary that evokes both the cold, invisible workings of neural networks and sticky bodies losing themselves at a rave, united by a heartbeat.

“Was he generous?” is the question that Simon’s parents are forced to answer as they struggle over whether to let the doctors remove their son’s organs. The show itself feels generous, open to feeling as a source of wisdom. As one of the show’s lovelier lines says of surfing—and, implicitly, of nearly everything else in life—“You only get one wave, then you pass it on.” As anyone who has ever been in an emergency room knows, in a crisis some clichés ring true.

There is a ravenousness in midtown right now, after a frustrating few years, for Broadway to get behind some great new musical. Will “Galileo” break through? Lin-Manuel Miranda’s “The Warriors”? “Wanted”? In late October, a hot contender débuted: the London transfer “The Curious Case of Benjamin Button,” which had a celebrated run there. In New York, some critics found it twee, but I adored this small, oddball fable about a man aging backward. The production actually shared a lot with “The Heart,” even though it was scored with Celtic sea chanteys. It, too, is a countdown show obsessed with mortality, a stylized tale in which actors swap roles. It, too, had a lyrical directness that risked cliché in pursuit of elemental feelings.

But what felt most notable about “Button” was its structure, which, like “The Heart,” featured an ensemble telling an individual’s story in unison—in this case, down to the thoughts inside Benjamin’s head. Both plays are part of a cadre of hive-mind musicals, along with an earlier Ashley-directed project, “Come from Away” (which, like “Button,” has a Celtic-folk score). These shows are explicitly focussed on communities, not individuals—a hospital in “The Heart,” a fishing village in “Benjamin Button,” a rural Canadian town in “Come from Away.” They’re romances about systems, riffing off the choral storytelling of such classics as “A Chorus Line” and “Sweeney Todd” or the clever identity-flipping of “Operation Mincemeat.”

There’s another play in town that employs a similar technique, more austerely: the song cycle “I Became We,” written by Mona Pirnot, with soaringly lovely music by Jack D. Coen. At the Linda Gross Theatre, sixteen singers stand on risers, holding green choral folders. There’s a conductor and a piano. It felt like church until we heard the first line, which was sung as solemnly as Handel’s “Messiah”: “I saw a segment on ‘Jimmy Kimmel Live!’ called ‘What Do You Know About the Female Body?’ ”

What followed was the funny, philosophical narrative of a successful New York playwright in her mid-thirties. She’s got friends to dish with; she adores her mother, a math professor, and her “jumpy and nervous” husband; she is certain that she doesn’t want children. When she goes to a boring party in Brooklyn, a friend passes her a baby, who—as the chorus sings, in joyful, slightly frenzied counterpoint—starts “squirming, squirming!” and “screaming, screaming!” And then there’s a sudden, destabilizing shift in tone: a solo soprano begins singing mournfully, “She’s so small / She’s so small.”

It seems, at first, that this will be a story about fertility—or infertility. But the narrative never goes quite where we expect, its idiosyncratic turns intensified by the singers’ communal delivery, like a catechism or a shared consciousness. Nobody “plays” the narrator; nobody acts out her behavior. They just sing her thoughts, without comment.

Why did this pack such a punch? Maybe it was because of the tension between the elevated harmonies and the down-to-earth words. Maybe it was because the performance framed one person’s inner monologue—It is wonderful to see people love my talented mother! Why am I crying at this Adam Sandler movie?—as a grand, even sacred project. When the payoff arrived, it reduced the audience to sobs as heavy as any I’d heard at “The Heart.” I suspect that we were all thinking about our own lives. It was impossible not to. ♦