His latest project, Richard Linklater’s movie adaptation of the Stephen Sondheim musical “Merrily We Roll Along,” to be filmed in real time across nearly 20 years, unites him with his childhood bestie Beanie Feldstein. And on Sept. 29 at Radio City Music Hall (and in a Netflix concert special to follow), he’ll perform tunes from “Sing to Me Instead,” his debut album released in March, viewed by some fans as a public coming out, even though at 12 Platt told his parents he was gay.

At a TriBeCa photo studio recently, Platt, who turns 26 this month, riffed softly to Maggie Rogers tunes in the aching falsetto that moved “Evan Hansen” audiences to tears, before heading to a rooftop garden to talk about the convergence of art and life.

These are edited excerpts from the conversation.

Let’s begin with your desire to move on from “Dear Evan Hansen.”

I think it’s like 99 blessings and one curse, that experience. Because it opened every possible door, and it was my absolute to-the-T dream come true, as far as all I ever wanted to do was originate a role in a musical, and the Tonys of it all, and the fact that it was [the songwriters Benj Pasek and Justin Paul]. It kept topping itself.

But the one underhanded thing when something goes so well and fits like a glove is that people have a hard time divorcing you from that character. And I started to feel a little bit like I was having to present as him and amplify my nervousness and my anxiety and my sheepishness. I wanted to remind myself that I can transform into a lot of different kinds of people and not just into that type of kid. And so I felt like something markedly different, that still used the right tools, would be the right next move.

So what should we expect from Payton and “The Politician?”

Payton is a young kid who’s hellbent on being president of the United States, and it’s one of the most natural things to him to strive for that power and that significance. And I think he has a lot of instincts to do good. But he’s also incredibly self-serving and somewhat egomaniacal, and his main goal is to make something of himself for not necessarily the right reasons. The show is sort of a microcosm of American politics, and it certainly deals with the buzzwords of elections and debates and gun control and sexual and gender fluidity — headline things. But in an overarching way, it’s also about a lot more human conversations like authenticity and what’s it like to curate yourself. How do you share who you are? And how do you feel for other people?