Transcript for 'Dear Evan Hansen' star Ben Platt on how he, the cast perform emotional musical
It's ironic that a musical about people struggling to connect is connecting so strongly with audiences. "Dear Evan Hansen" has taken Broadway by storm and thrust its 23-year-old lead into superstardom and a Tony nomination. Here's ABC's Deborah Roberts. ??? ??? snoes. Reporter: It's anthem for anyone who's ever felt alone. ??? When you're broken on the ground note. Reporter: You will be found. The powerful message of the musical "Dear Evan Hansen." The heart-wrenching show about teen anxiety, suicide, and the pressures of social media has taken Broadway by storm. ??? When you've fallen in the forest and there's nobody around ??? ??? do you ever really crash do you even make a sound ??? Reporter: For fans, 23-year-old Ben Platt, who plays Evan, has become a hero. Oh my gosh, you're so amazing! Thank you. I think the reason the show and the character are so universal is because nobody escapes feeling like an outsider completely. Reporter: The show's become a phenomenon, nominated for nine tonys, including best actor for Platt, who many remember as the misfit turned singing sensation from "Pitch perfect." ??? Now everybody knows I've got the magic ??? ??? true friends on a perfect day ??? Reporter: On stage he gives an emotionally charged transformation into a teen crippled with anxiety that leaves the audience in tears. At the end of the day, it's about people trying to figure out how to connect with each other. In a society right now that is superficially people are connecting all the time in a million ways but that's making it harder to find the ones that are meaningful and that can validate you a human being, define you yols a human being. ??? When it all feels so big ??? Reporter: We caught up with Platt and costar Rachel bay Jones, also nominated for a Tony, who plays his mom Heidi, at the lamb's club blocks from the music box theater, where tickets are nearly impossible to snag. I was sandwiched between a teenage girl who was sobbing in a big guy in a camouflage hat who began sobbing. Why has this hit such a nerve with parents, with kids, with people who feel sort of like outsiders? What is it? I feel like all of us have experienced feelings of isolation, of remorse, of guilt, of not being able to connect with each other, whether it's our family members or people in our community. And I think all of us need to be seen for who we are. ??? Buddy you and I 4 forever ??? Reporter: Platt says conzaying all that emotion eight times a week leave him and cast members emotionally and physically exhausted. How do you find it? Your manner ems, your tics, your singing, crying, you're singing while you're crying. How do you pull that off? You know, it's multiple answers. The main one being that eight of us are all a really tight-knit family and we hold each other up. Reporter: Hard to believe the powerful musical consists of only eight actors. Yes, yes, everyone's pretty spent emotionally and physically. But the show ends on a really redemptive note and fills us back up and gives us hope. Me and Rachel get to go off stage and hug each other and that's helpful too, a nice button to the evening. ??? When it all feels so big ??? Reporter: To lighten that emotional load, backstage a wall of jokes to help leave the sadness on stage. Like this one. How do crazy people go through the forest? They take a psychopath. Reporter: Rachel bay Jones gave us a rare look behind the scenes. We're over the stage? We're tech atly over the stage. This is where all the guys, except Ben and our understudies, have their dressing rooms. Reporter: With where the cast hangs out before each performance. I'm such a fan of all of you. Thank you so much. I'm so excited to see it again. I'm a fan of the show. Well, you know. I had to bring it. Reporter: Platt doesn't socialize before the show. Saving all his energy for the stage. This is where all of the magic preparation happens for Ben. We won't bother Ben. He's got a lot going on. I can hear him vocalizing. Reporter: 30 minutes before showtime and a sold-out crowd. I always love this view, looking out at the audience, it's so gorgeous. Reporter: Outside fans are already lining up. Like these teens from Utah. Kind of like a signal of hope that eventually you will be found. And there's someplace for everyone anywhere and you just have to find it. Reporter: The message of the show is spreading beyond those lucky enough to get tickets. ??? When you fall in the forest there's nobody around ??? ??? you can really crash do you make a sound ??? Reporter: These YouTube tributes a sample of the vast response the show is getting online. The most beautiful thing is the way people are responding. We really feel -- it's everything an artist could ever dream of. Reporter: Just days before the Tony awards, Platt is riding the wave. Even getting his own caricature at Broadway's famous sardy's restaurant. Are you ready for, and the Tony goes to? Ben Platt. I'm ready for that. Toy toy toy toy toy. No most of all it's just we have loved the piece since we started 3 1/2 years ago. We're trying to hold on to the ride and understand what's going on before it passes us by. So exciting. Reporter: Whatever happens on Sunday night -- ??? you will be found ??? Reporter: No doubt Platt, Jones, and the rest of the cast already feel like winners. What's your biggest hope for people as they leave this theet? Hopefully people not being so hard on themselves and knowing in your darkest moments, when you find yourself in the pit where you can't say that you're happy with the person you see in the mirror, that you know that you're the farthest thing from alone in that. ??? If you only look around you will be found ??? Reporter: For "Nightline," I'm Deborah Roberts in New York.
This transcript has been automatically generated and may not be 100% accurate.