The Met Cloisters were alive with the sound of music on a frigid January afternoon. Six nuns in white surrounded a seventh dressed in black, and all were singing. The scene was beautifully formal but it also felt organic, as if the women had been there for centuries.

Watching a rehearsal of Magos Herrera and Paola Prestini’s opera “Primero Sueño,” which the Metropolitan Museum of Art is presenting tomorrow through Sunday, Ronda Kasl, a curator of Latin American art at the Met and a consultant on the project, could not contain a smile. “This is so exciting,” she murmured as chants bounced around the limestone walls that keep the world at bay.

Based on a mystical poem from 1692 by Sor Juana Inés de la Cruz, the 17th-century nun and proto-feminist polymath, “Primero Sueño” (“First Dream”) was conceived as a processional opera that would take over the Cloisters as it meandered from room to room, audience in tow.

“The poem is about a soul journey,” the director Louisa Proske said. “So we thought, ‘What if we translated that soul journey into a physical journey at the Cloisters spaces?’ Each room has a new possibility of how the audience relates to the performers.” In some rooms, Proske said, people sit together on benches, while in others they are free to roam around the singers.

After Proske, a founder of the innovative Heartbeat Opera company, directed Virgil Thomson and Gertrude Stein’s “The Mother of Us All” at the Metropolitan Museum in 2020, the Met invited her to stage another piece in a museum space. She had her eye on the Cloisters, so when the New York composer Prestini mentioned that she’d been working on a Sor Juana project with Herrera, Proske knew she had found what she was looking for.