The Calloway is on fire right now, and most of that fire has a name: Esmeralda Voss. The Burning Season, which opened last night on a stage dressed in corrugated tin and bruised amber light, is exactly the kind of ambitious, dangerous musical Broadway keeps saying it wants and then doesn’t know what to do with when it actually shows up. It is mostly extraordinary. Mostly.

Let me be more precise. Voss as Marisol — a Dominican seamstress turned labor organizer in 1920s Manhattan — is the performance of this season. She has the quality that great musical theater voices possess: the technique disappears, and what’s left is just truth. When she delivers “The Needle and the Law” in the second act, the Calloway held its breath for sixteen bars. Not polite attention. Actual silence from seven hundred people who forgot they were sitting in seats. She broke them open and they didn’t even know it was happening until they were already undone.

The show around her is doing two different things, and only one of them is working.

Composer and lyricist Domingo Ferreira has written a score that earns its ambitions — big choral numbers that swell and fracture at the right moments, ballads that hide their harmonic sophistication until you’ve already been wrecked by them. The orchestrations, twenty-two pieces conducted from the pit with real intelligence, do what orchestrations should do: they underline without explaining, they breathe when the voice breathes. The orchestra alone is worth a second trip downtown.

Director Gian Morales has built something genuinely beautiful in the second act. The staging of the march sequence — the ensemble pressing downstage as the corrugated panels rise to reveal a fractured skyline behind them — is the kind of physical theater that makes you understand why directors exist. It’s not a pretty picture. It means something. The image tells you what the song is about before a single lyric lands.

But the first act, mija, is a problem.

Morales keeps pulling focus to the ensemble through the early scenes. In theory this honors the collectivist politics of the material. In practice it delays our commitment to Marisol past the point where the delay is still interesting. The organizing sequences are choreographed with energy but staged in nearly identical tight formations, one after another, until the eye goes dull. By the time the first real crisis arrives, you’ve spent so long watching geometric patterns that you’ve lost the stakes they were supposed to be building.

And then there is Rafael Serrano as Marisol’s estranged husband, Bernardo. Serrano is a handsome man with a serviceable baritone and almost nothing behind his eyes. He is doing the minimum required to be present on a Broadway stage, and he knows we know it, and he doesn’t seem particularly bothered. Every time Voss turns to face him in a duet, she is acting at a wall. Their reunion scene in Act Two — which on paper should be devastating — lands soft and short because Serrano gives her nothing to work with. Voss finds a way anyway. She always does. But she shouldn’t have to.

Here is what surprised me about last night’s audience: they came alive exactly when they needed to. The Calloway crowd, which skewed subscription-heavy and patient, sat through Act One’s longueurs without complaint and then did something I have not heard in that house in three seasons — they gasped, out loud, when the march sequence resolved into a stage picture I will not describe because you need to see it yourself. And at the curtain call, when Voss stepped forward, they were on their feet before her foot hit its mark.

You should go see The Burning Season. Go because Esmeralda Voss is doing the rarest thing a musical theater performer can do — making you feel something true about people who lived in circumstances you will never live in. Go because the score is the real thing. Go because the second act is worth every moment of the first act’s hesitation, and because a Broadway house willing to put a labor organizer at the center of its stage deserves your ticket money.

Arrive knowing the first act needs another few weeks of previews. Forgive Serrano his distance and let Voss carry you, because she will.

Estamos aquí.