One night in 1984, Compay Segundo, the Cuban singer and guitarist, heard in his dreams what would become his signature song.

“I woke up hearing those four sensitive notes,” Segundo recalled later on. “I gave them a lyric inspired by a children’s tale from my childhood, ‘Juanica y Chan Chan.’”

A hypnotic account of peasant life in Cuba, “Chan Chan” has a peculiar power, with four circular, mesmerizing opening chords that make it instantly recognizable. It gained a regional following when it was cut by the guitarist and singer Eliades Ochoa. But a recording of the song, in 1996, by a group of celebrated Cuban musicians who had been assembled for an album to be called “Buena Vista Social Club,” would become a phenomenon.

Now more than 25 years after its release, the best-selling world music album of all time has made it to Broadway in a new musical also titled “Buena Vista Social Club.” “Chan Chan” is among eight of the album’s 10 songs featured in the show and, perhaps not surprising for such a dramatic and mysterious track, it plays a crucial role in a pivotal moment in the story.

As the album of mostly older Cuban standards became a global sensation upon its release in 1997, Segundo’s song — about sifting sand by the sea and clearing a straw path along a journey to Cuban towns — became a standout all its own. “Chan Chan” was never released as a single, but the opening track has been streamed more than 250 million times on Spotify, almost three times more than anything else on the album. (That number is roughly the same as Toni Braxton’s “Un-Break My Heart” and Hanson’s “MMMBop,” both No. 1 hits in 1997.)

So the creative team of the “Buena Vista” musical — now playing at the Gerald Schoenfeld Theater, after premiering Off Broadway in 2023 at Atlantic Theater Company — was well aware of what the audience’s expectations would be for this particular song. The problem, though, is that while “Chan Chan” is the album’s most recognizable “hit,” it’s moody and atmospheric — not the kind of high-energy showstopper that’s easy to build an opening number around or place as a finale.

“We knew we had to use it,” said Marco Ramirez, who wrote the book for the show, which bounces between 1956 and 1996. He said they were thinking of the show as a concert, and debated: “Do we open with it and get it out of the way? Do we save it for the end of the show? Do we save it for the encore — like, ‘Aha, we didn’t forget!’ It was kind of fluid where we would put it.”

In Ramirez’s first draft, “Chan Chan” was what he called a “‘Moby Dick’ story” for Segundo, who was 89 at the time of the “Buena Vista” sessions — his attempt to write a song for the ages. “It was basically ‘One Song Glory’ from ‘Rent,’ except that it was Compay Segundo saying, this is how you live forever, through your music.”

Dean Sharenow, the production’s music supervisor, noted that the show was not only struggling to find the right use for “Chan Chan” but also working out how to balance Spanish-language songs and English dialogue.

“We tried at the end of Act One, we tried it as a performance, maybe in the studio at one point, and it just never connected,” he said. “This song is so famous, you have to deliver it in a way that has emotional impact, but the song itself is very chill.”

Eventually, “Chan Chan” found its place at the musical’s dramatic pivot point, when Omara Portuondo, a young singer in 1950s Cuba, has to decide whether to fly to New York with her sister to fulfill a coveted recording contract or remain in Havana as the revolution begins.

“That moment of the breakup of the sisters represents the country fracturing, people leaving and people staying,” said the musical’s director, Saheem Ali (a Tony nominee for the play “Fat Ham”). “It’s a crossroads moment — the song is about directions, but also now it’s literally about the crossroads of our main character deciding, is she going to go left or is she going to go right?”

This number, performed by the onstage band, is the one time in the show that the music is used more like a film score than a stage performance. It’s the only song that’s not delivered by the actor at the center of the scene or as a showcase for the band — serving more as interior commentary than as narrative, a subtle choice for the one song many in the audience are waiting for.

The team started adding layers. In addition to the rolling figure on the small guitar called a tres and a darting trumpet solo, Marco Paguia’s arrangement incorporates several themes and melodies from other songs in the show. “Music and memory are so much part of the play and ‘Chan Chan’ has a lot of that,” he said. (In her review of the production for The New York Times, Elisabeth Vincentelli wrote, “The music is center stage, and we immediately understand its power as a communal experience that binds people.”)

DANCE IS ALSO a big part of “Buena Vista Social Club,” and especially on “Chan Chan.” The choreographers Patricia Delgado and Justin Peck wove in callbacks to previous moments in the show, as well as balletic elements for the ensemble. “Ballet is such an important part of Cuban culture,” Delgado said. “We wanted to figure out a way to bring out that lyricism, that adagio quality — like pulling taffy, nothing staccato.”

Delgado (who said that “Chan Chan” was “omnipresent” in her own Cuban family) added that as the staging developed, it became the number that required the closest collaboration from the creative team. “It was really hard to work on ‘Chan Chan’ unless all the departments were there,” she said.

As a result, two weeks before opening night, the number still wasn’t fully finalized. “No surprise, that’s the song we’re still working on,” Ali said in an interview earlier this month. “We’re still trying to figure out what is the right length, what is the right feel?”

The distinctive opening notes of “Chan Chan” often draw applause but, Sharenow said, it’s more significant that the audience then goes silent. “They don’t know what’s coming,” he said. “They’re being told a story in a different way than they had for most of the previous music.”

Ali added that Segundo “tapped into some chords that just touched all of us. You feel something, but you don’t know exactly what you’re feeling.

“It became this blanket that can contain everything that we want in our story,” he added. “Not everything can support that, but this song has the breadth and scope to do it.”

According to Leila Cobo, chief content officer Latin/Español for Billboard, the opening of the song may even be the key to its unlikely popularity.

“When I first heard it, I never thought it was anything other than an old Cuban guy singing an old Cuban song,” she said. “But listening with new ears, that beginning is almost like a rock song. It’s not like a traditional Cuban guitar song.

“I’m not comparing ‘Chan Chan’ to ‘Livin’ la Vida Loca,’” she continued, “but when you hear ‘Livin’ la Vida Loca,’ it’s a Latin track, but it has enough of the mainstream that it’s palatable. ‘Chan Chan’ doesn’t sound like folklore when the song starts — then he starts singing, and you realize it’s in Spanish, and he has the voice of an older man, but you’re already in it. I think if it began differently, it might not have been the track that took off.”

It’s also a guiding light for Cuban musicians like Camila Cabello. “It’s slow and sultry,” she wrote in an email, “it reminds me of a nostalgia of being in Cuba but it’s always timeless. Every artist aims to make a song that feels both classic and personal no matter when you play it, and ‘Chan Chan’ feels that way to me.”

David Bither, president of Nonesuch Records, who played a key role in partnering with World Circuit Records, the label behind the “Buena Vista” album, recalled the first playback of the project. “There was something immediately magical about it. Maybe I’m just reinterpreting history, but the first time we heard it, we felt it.”

And it is still being felt by new audiences more than 40 years after Compay Segundo wrote a simple song with folk-tale lyrics and years after it kicked off an album that changed the history of his country’s music.

In some ways, the melody that came to the old guitarist in his sleep has come full circle.

“That moment in the show is a dream,” Sharenow said, “and you need a song that’s like a trance to put you there.”