When director Michael Gracey met with Benj Pasek and Justin Paul in 2013 — years before anyone in Hollywood knew who they were — he explained his vision for a bold, original movie musical based on the life of circus impresario and visionary P.T. Barnum. But he was clear from the start: This was not a biopic. Rather, The Greatest Showman, starring Hugh Jackman, would be inspired by the ostentatious entrepreneur and his razzle-dazzle persona. As such, the larger-than-life soundtrack should be ahead of its time, too. Hence the film's contemporary pop sound.

Of course it took some time for Pasek and Paul to wrap their heads around Gracey's idea at first. The duo, who met as undergrads in the University of Michigan's celebrated musical theater program, are known for putting life's everyday moments to song, but for The Greatest Showman, the first-time feature director pushed them to think bigger and bolder. "We were like, 'Cool. We don't really get that exactly, but it sounds cool in a hypothetical sense,'" Paul told MTV News at a press day for the film in New York. "So we went to work trying to serve that vision and write pop songs that could be entertaining." The first song they came back with was "A Million Dreams," the film's wistful opener and by far the soundtrack's most traditional musical theater entry.

Nearly five years later, and Pasek and Paul are the newly minted faces of the movie musical genre with hits like La La Land, Dear Evan Hansen, and a forthcoming Disney collaboration with the legendary Alan Menken under their belts. But their Hollywood aspirations all started with The Greatest Showman. From flashy, anthemic numbers like "This Is Me" to intimate ballads like "Tightrope," MTV News asked the Oscar- and Tony-winning duo to break down some of the memorable tunes from the flick.

"A Million Dreams"

Originally, "A Million Dreams" was just a song for young, impoverished Barnum (voiced by Ziv Zaifman), but in collaboration with Gracey, Pasek and Paul widened its narrative scope to allow for a significant passage of time. So the song begins with young Zaifman and ends with Jackman, Barnum now all grown up and married to the girl of his dreams, Charity (Michelle Williams).

"That's what is kind of crazy about what you're able to do on film that you can't do on stage: You can cut away and show this young man and young woman growing up," Paul said. "That was Michael's vision, and what he turned it into."

For her part, Williams also got a chance to sing and dance alongside Jackman. (Williams made her Broadway debut in 2014 as nightclub singer Sally Bowles in the revival of Cabaret.) In working with the four-time Oscar nominee, Paul said, "She sounds beautiful... We had a lot of fun in the studio working with her. She added a lot of warmth to the character and her performance."

"Rewrite the Stars"

In the film, Zendaya plays a young trapeze artist named Anne who falls in love with Zac Efron's determined impresario, Phillip. Their love defies the odds — and gravity. Their intimate, acrobatic musical number, "Rewrite the Stars," is a real showstopper in the film, as Anne and Phillip take to the sky for a high-flying duet on weighted trapeze ropes.

Gracey came to Pasek and Paul with a song brief that outlined the fantastical moment. "He was like, 'This is this moment of these two lovers who can't be lovers but want to be, and the other element is they're flying through the air.' We're like, 'That's crazy and awesome,'" Paul said. "As we wrote it, we wanted to have in mind the idea of the electricity between these two characters... there's that longing."

The emotion of the moment only intensified once Efron and Zendaya were cast in the roles. "When we heard them sing it for the first time," Paul recalled, "it was like, 'This is fire.'"

"Who doesn't want to see Zac and Zendaya kiss, you know?" Pasek added. "That's all you want... They have such amazing chemistry." And, lucky for Pasek and Paul, they also had "cool" voices. "We were told to write the song in a contemporary way, but you never know who the performer will be," he said. "Zac and Zendaya both have really cool, really contemporary voices. They sound like pop stars to me when I listen to it."

But it wasn't all smooth sailing. During their pre-production workshop with the actors, there came a point when Pasek and Paul realized that "Rewrite the Stars" just wasn't working. Seeing as the number directly follows an emotionally heavy scene between Anne and Phillip, Gracey didn't want the moment to immediately transition into song; he wanted it to linger. That's when Zendaya stepped in and suggested starting with a bit of acapella.

"She was like, 'Why does there have to be music?'" Pasek recalled. "And we were like, 'Well, there has to be music. It's a song!' Then we go to the corner, and we're like, 'Maybe she's right. It's kind of a good idea. Should we admit that?'"

Ultimately, it was the right call. It elevated the scene's emotional weight and captured the intimacy of two star-crossed lovers at a crossroads. "So we looked at Zendaya," he concluded, "and we were like, 'You're the queen of all things. You should be doing our jobs too.'"

"This Is Me"

"This Is Me" is the anthem of the film. It's a powerful song for anyone who has ever felt different or oppressed for being themselves. It's the emotional moment when the Oddities, led by Keala Settle's bearded lady, Lettie Lutz, step out of the shadows and make themselves known to an unforgiving crowd. Given its important message of empowerment and inclusion, it's no surprise that the song has resonated with audiences and critics, alike. It's already been nominated for a Golden Globe, and it made the Oscars shortlist for Best Original Song. But the road to getting there wasn't easy; the song, which was originally written for the character of Tom Thumb, went through many iterations before it became the anthem it is now.

"Tom Thumb sang it and it was just five guys [Paul makes a strumming motion] and a ukulele," Paul said. "It was sweet." But not nearly as emotionally resonant as Gracey wanted it to be.

"We couldn't really crack it, though, and Michael was like, 'I really think that there needs to be something that feels anthemic for the Oddities about how they're feeling and claiming identity,'" Pasek added. "We couldn't figure it out, and then when we began to think about it from the perspective of, and in the voice of, the bearded lady, Keala Settle, we knew that she had this big, powerhouse voice and she's such a wonderful actress, so when we began to write for her voice specifically it began to open up the process for us, and we started working on that song."

As you can see in the video above, filmed during during a workshop presentation for Fox executives, Settle pours her entire heart into the song, truly making it her own.

"The Other Side"

The Greatest Showman is Jackman's show, but for the rousing number "The Other Side" he shares the stage with High School Musical heartthrob Efron — and the duo ignite our screens with an electrifying song about... a business negotiation. For Pasek and Paul, that was the challenge: "How do we want to try and make this sound cool?"

Lucky for them, Jackman and Efron brought their innate charisma to the performance. "We wrote the song anticipating from these two actors that there would be such muscularity that they would bring to it," Paul said. "It's fun to write a music theater number that's a negotiation for these two guys with their bravado and showmanship trying to one-up each other." So, the duo approached it as a duel — one with plenty of choreography.

"They're jumping on the bar, it's a dance-off, sing-off," Paul added. "That moment is really electric. Once we knew it was going to be Zac with Hugh, it was like, 'That's a moment I want to watch.'" (Anyone who's seen their dazzling performance on the big screen knows that choreographer Daniel 'Cloud' Campos, who plays the bartender, is the real MVP of that scene.)

When it comes to working with Jackman, a veteran of the stage and screen, Pasek and Paul admit that their early workshops with the actor were terrifying.

"He's such a legend! He's the song and dance man of our time," Pasek said. "In the beginning we were trying to figure out. Is this song working? Can we hear Hugh Jackman singing this song? We would be in rehearsal rooms with him, pitching him new songs, and we were completely terrified of what he was going to say. But he's such a kind, wonderful collaborator that getting to develop it with him and Michael was kind of incredible."

"Since we didn't know him before, we had no idea to the degree of his work ethic," Paul added. "He's always giving 110 percent. He's the first one there and the last one to leave. It makes everyone in the room question themselves and their value as a human being and then be like, 'I've got to work harder. I've got to be better.'"

"You can't slack off when Hugh Jackman is in the room," Pasek said. And he knows that from personal experience. "I remember walking into a room once — we were called in at 8 a.m. and I walked in at 8:02 — and, in a sweet way, Hugh says, 'Benj, where ya been?'"

"Tightrope"

It's hardly a surprise that the sweetest, most intimate song of the film belongs to Williams, whose solo number "Tightrope" is a wonderful showcase for her acting and singing talents. According to Pasek and Paul, it was a true collaboration with Williams, who grounded the song in real emotion and heartbreak.

"She brings a real intimacy to everything she does," Pasek said. "And groundedness," Paul added. "That song could have been really theatrical, but she's such an actor's actor that she brings a grounded focus to the song that feels very real. It's not musical theater-ish in the way of a big, look-at-me performance. It's very small and very intimate, and that draws you in. That's Michelle Williams."

The Greatest Showman is currently in theaters.