Thomas Kail, the Director of the new Broadway play, “Hamilton” at the Richard Rogers Theatre in New York City. (Todd Plitt/For The Washington Post)

Before Thomas Kail ever met Lin-Manuel Miranda, he was annoyed by him — or the idea of him, anyway. Kail was a senior at Wesleyan University, about to stage a production of a play he’d written titled “Re: Peter,” when he learned he had to share the performance space with a freshman who had composed a musical called “Seven Minutes in Heaven.”

“I thought, ‘Who is this guy who was taking our lights?’ ” Kail recalls, summoning an upperclassman’s sense of superiority. “A freshman — in a dorm? Well, he wrote a musical. That’s so cute! Little did I know I’d end up spending 13 years of my life working with him.”

Kail tells the story by way of correcting a popular misconception about the origins of the team responsible for the electric new musical “Hamilton”: He never actually knew Miranda during the single school year, 1998-1999, that their university lives overlapped. Nope, Kail and Miranda sealed no personal or creative bond at the Connecticut school. Kail had nothing to do with the earliest version of another musical that Miranda wrote and performed at Wesleyan, “In the Heights” — the show that Kail, a few years later, would help to develop and direct after they finally did meet, in 2002, and that would go on to collect the 2008 Tony Award for best musical.

“Hamilton” director, Thomas Kail, from left, and cast members Daveed Diggs, Lin-Manuel Miranda and Anthony Ramos at a rehearsal at the New 42nd Street Studios. (Charles Sykes/Invision/AP)

Once they fell into each other’s orbit, their symbiotic connection became airtight and, it’s fair to say, has evolved into one of the most artistically important partnerships on Broadway today. With Miranda as composer and star, and Kail directing, they are this week marking the official Broadway opening of “Hamilton,” the hip-hop-infused musical about the turbulent life of Founding Father Alexander Hamilton. And, if all goes as planned, it will solidify their perch in rarefied air, as musical-theater personages to be reckoned with.

Miranda, who plays the title role in an ethnically diverse cast 20 strong, has gotten the lion’s share of the attention in the run-up to Thursday night’s opening at the Richard Rodgers Theatre. It’s been a heady preamble, beginning with an acclaimed off-Broadway run at the Public Theater, generating the most intense buzz for a new American musical since “The Book of Mormon.” But by all accounts, the Alexandria-born Kail, who got his first taste of theater as a soccer-and-baseball-loving athlete at Sidwell Friends School, is worthy of more of the spotlight than he has so far been apportioned. As the project’s commander in chief — the grounding, supportive yin to Miranda’s restlessly imaginative yang — he’s guided Miranda and the ensemble to what many already are placing in the category of landmark achievement.

Miranda notes that his best work has been with Kail: The shows they’ve done without each other on Broadway — Miranda co-writing the musical “Bring It On,” Kail directing a pair of sports plays — have been far less distinguished. Even when they’re off doing separate projects, though, Miranda relies on his director-friend for counsel.

“So whether it’s formal or informal,” Miranda says in a phone interview, “we’re stuck with each other.”

Oskar Eustis, the Public Theater’s artistic director, counts Kail’s work on “Hamilton” as “one of the most extraordinary leadership jobs I’ve ever seen.”

“Tommy is deeply concerned with, ‘How can I deal with this person so that they will be at their best?’ ” he said. “I’ve never quite seen a leader who’s so selfless and at the same time is so strong. And in the American theater, that combination of qualities is rare.”

Daveed Diggs, Okieriete Onaodowan, Anthony Ramos, and Lin-Manuel Miranda in Hamilton, with book, music, and lyrics by Lin-Manuel Miranda, inspired by the book “Alexander Hamilton” by Ron Chernow. (Joan Marcus)

* * *

This, then, is a moment of arrival for the 38-year-old Kail. And for a musical theater desperately in need of leaders of every stripe, it couldn’t be a more timely ascension. Lamentably passed is the era of enduring collaboration between visionary directors and gifted Broadway composers and lyricists, the kind of lasting relationships fostered by such directing giants as Harold Prince and Bob Fosse with the likes of Stephen Sondheim and John Kander and Fred Ebb. As “Hamilton” is only their second Broadway musical together, Kail and Miranda may feel as if it is still early days. But the caliber of work in “Hamilton” reveals that they and their partners — choreographer Andy Blankenbuehler and music director Alex Lacamoire — have an opportunity to both break the mold and recast an earlier one. To become a team that stays together, propelling the form forward.

Kail, a mile-a-minute talker who projects a mix of confidence, deference and affability, seems to be built for the chaos of creation.

“You feel from the first moment that the spirit is so big,” says Renée Elise Goldsberry, who plays Angelica Schuyler, the Hamilton sister-in-law who remains secretly in love with him. Goldsberry recalls a calming gesture by Kail during her nerve-racking audition that, for her, encapsulated his generous nature:

“So Tommy was like, ‘Great job,’ and gave some wonderful notes on how to do it again. Somewhere in the back of my head, I thought, ‘They can’t tell I’m nervous.’ But after he finished giving his notes, he slid a glass of water across the table toward me, really subtly. And I just thought, what a first encounter — he doesn’t miss anything.”

For a guy whose leadership philosophy is rooted in the idea of every individual’s contribution being vital, it seems appropriate he would become immersed in a project so intrinsically about democracy.

“My job was not to have the best idea in the room at any time but to identify the best idea,” he says in “Hamilton” producer Jeffrey Seller’s office in midtown Manhattan. “That was an unburdening. If I could do that, be able to point to the thing that sounded like the finest idea of the day, then ego went out of it for all of us.”

“My job was not to have the best idea in the room at any time but to identify the best idea,” Kail said. (Todd Plitt/For The Washington Post)

Daveed Diggs (center), Anthony Ramos, Carleigh Bettiol, and Thayne Jasperson in “Hamilton.” (Joan Marcus)

* * *

What makes someone a stage director? For Kail, it was a gradual process, and only incidentally an academic one. The son of a lawyer and an archivist, he was an athletics-crazed kid who thought of being a sportscaster. (It was a very Washington childhood: The Kails’ next-door neighbor in Alexandria was Paul Tsongas, the senator and presidential candidate from Massachusetts, who became a family friend.)

He was by no means a theater kid; he didn’t even watch his first Tony Awards on TV until he was 24. At Sidwell, a requirement to sample a drama class led to encouragement by a highly regarded drama teacher, John Elko. Then at Wesleyan, friends who were working on a play enlisted him. The passion got its first real ignition during a junior-year exchange program that sent Kail to Dartmouth, where he sat in on a class being taught by Pulitzer-winning playwright August Wilson, author of “Fences” and “Joe Turner’s Come and Gone.”

“We read ‘Joe Turner’ and I had this burning question. I was so nervous to ask it. I’d never met a playwright,” Kail says. “I came up to him afterwards and Wilson was there lighting a pipe and I said: ‘The outhouse in “Joe Turner,” it’s not really an outhouse. It must symbolize something.’ And I went on talking for about three minutes.

“He looked up and said, ‘Sometimes an outhouse is just an outhouse.’ And he walked off into the snow. And I thought: ‘I want to write a play.’ And I went back to my dorm room and I flipped open my computer and I sat there. It was noon, and the next thing I knew it was 6 o’clock. And I thought, ‘When I get back to Wesleyan, I’m going to direct this.’ ”

He did, in fact. It was “Re:Peter,” and the experience kindled a deeper desire to follow a dramatic path. After graduating, Kail landed a $100-a-week job as assistant stage manager at the American Stage Company in Teaneck, N.J., living in a windowless basement apartment in another Bergen County suburb. “I didn’t show my mom the first three places I lived,” he says, laughing.

The early 2000s were the critical networking phase of his life. In 2001, Audra McDonald hired him to be her assistant. (“She was an incredible boss because all she cared about was I got my job done. It didn’t matter if it took 40 hours or 20 hours.”) Around that time, he and his old Wesleyan buddies — one of whom, John Buffalo Mailer, was a son of author Norman Mailer — formed a theater company, Back House Productions, through which Kail continued to develop as a director. And they had the good fortune to be introduced to Allen Hubby, owner of the Drama Book Shop on West 40th Street. Hubby was looking for a start-up company to produce plays in a 50-seat performance space in the store’s basement. Kail’s group grabbed the opportunity.

Lin-Manuel Miranda (center) and the company of “Hamilton.” Miranda was drawn to the story of this volatile and ultimately tragic figure, of humble immigrant origins and big ideas, who rose to power and influence over the new nation’s monetary system. (Joan Marcus/Joan Marcus)

* * *

Kail and Miranda finally met in the spring of 2002. The spark was instantaneous. Kail visited him at Wesleyan to talk about “In the Heights,” Miranda’s musical about life in a Latino neighborhood of upper Manhattan. Kail had been given the script and score by mutual friends two years earlier, and he was waiting for Miranda to finish school so that, if the two of them clicked, they could work on it in the Drama Book Shop’s theater.

“We sat for five hours that first meeting,” Kail recalls. “I felt like I’d been looking for him my whole life and I didn’t know.”

It was all that for Miranda, too. “I came into that meeting and Tommy is a tsunami, at that speed, hitting me with all this stuff,” he remembers. “I would say 50 percent of the ideas at that first meeting made it into the Broadway production.”

“In the Heights” ran for nearly three years and 1,200 performances, also at the Richard Rodgers, soaring far beyond where either of them imagined it would go. The trajectory of their follow-up Broadway show feels as if it has been plotted on yet another un­or­tho­dox graph.

“I was recently looking back through one of our G-chats where Lin said, ‘Hey, I got this book. It’s good,’ ” Kail says. “And I was like, ‘Cool. So what are you doing tomorrow?’ ”

The book was Ron Chernow’s exhaustive biography “Alexander Hamilton.” Miranda was drawn to the story of this volatile and ultimately tragic figure, of humble immigrant origins and big ideas, who rose to power and influence over the new nation’s monetary system in an indelibly American way. The songwriter’s first notion was to make a concept album, not a musical; when he was invited to the White House in 2009 for “An Evening of Poetry, Music & Spoken Word,” he performed a song from what he was then calling “The Hamilton Mixtape.” The performance was posted online.

“And then it started ricocheting around the world,” Kail says. “We sensed something else was happening here that could live beyond a concept album, as a show. There was a story to tell.” From the book, Kail says, “we both made a list that was like 612 things long of what we responded to. We went, ‘this moment, this event, this character,’ and we saw where they all intersected.”

Seller, a producer of “In the Heights” and best known as one of the original producers of “Rent,” attended a Lincoln Center “American Songbook” concert in 2012 at which Miranda, Kail and Lacamoire, the music director, presented several songs. Seller immediately wanted to produce a full-blown stage version. “I believe this is affirming in the most visceral way our pride in our country,” Seller says. “In a way that has never happened in my lifetime.”

The show was such a smash in its Public Theater premiere this year that it quickly acquired you-have-to-be-there status. In previews at the Rodgers, where it has amassed advance ticket sales north of $28 million, it’s again an audience magnet, of a magnitude that prompted President Obama to snare an aisle seat at a recent matinee.

Kail grasps, of course, the significance of this moment for him. He says, though, that he experiences it not as the potential triumph of any one person, but of the larger group that has made the moment possible.

“There is a line in ‘Hamilton’: ‘The world was wide enough for both Hamilton and me.’ There’s a reason both Lin and I have that line circled,” he says. “Because someone else’s success does not preclude your own ability to achieve.”