Three years ago, the show’s creators — Steven Levenson, who wrote the book; Benj Pasek and Justin Paul, the music and lyrics; and Michael Greif, its director — brought a group of actors together for the first time to read through the script. They’d been developing the story since 2011, and while they weren’t completely sure of what they had, it felt promising, and the producers were vigilant about controlling when and how word of it would eventually get out. Watermarked copies of the script were handed out and collected at the end of the session. Nondisclosure agreements were signed. “We came in for that first reading,” Mr. Platt recalled, “and they said, ‘We’re not going to tell you who he is or what the story is — we’re just going to read through and see what happens.’”
Three years before that, when he was 17, he’d auditioned for Mr. Pasek and Mr. Paul’s musical “Dogfight,” about a group of Marines on the eve of shipping out to Vietnam. “He was incredible,” Mr. Paul said. “But we’d begun casting the show, and the leads were all in their early 20s. It was one those casting moments when you know someone is so special, but you also know he just doesn’t fit.”
Mr. Pasek sent him a Facebook message the afternoon of the audition, mentioning this other idea they were developing and suggesting they stay in touch (“I was like, that’s nice, but nothing will ever happen,” Mr. Platt said). Over the next few years, they tracked his life and career — his performance in the 2012 film “Pitch Perfect” as Benji, the magic-loving misfit; his enrolling in Columbia University and then dropping out six weeks later to play Elder Cunningham in the Chicago production of “The Book of Mormon”; and eventually his assuming the role on Broadway in early 2014.
Mr. Platt said he was initially being considered for the “Dear Evan Hansen” role of Jared, the title character’s wisecracking friend, who spends much of the musical hurling abuse at Evan but is all in on the deception once he senses that Evan’s newfound social status might elevate his own. “I think Benj was the one who wanted to give me a shot to be the hero of the story, though,” Mr. Platt said. “And he convinced everybody that I should read for the lead.”
They needed an actor whose innate warmth and likability would help them figure out just how far Evan could go in the other direction, Mr. Pasek said — how egregious his actions could be, while still keeping the audience on his side. “It’s such a complex role; we were still trying to get a handle on what it was,” he said. “We went into that first workshop thinking, we’ll see what we think of Ben, and we’ll see if this role is written right. We’ll just see. Then, honestly, within five minutes into that first reading, Michael…