A concussion nearly derailed the actor’s fan-favorite turn as the madcap, black-and-white striped ghoul. But he recovered in time for the closing show.As Alex Brightman disappeared through the doorway to the Netherworld one last time at the Marquis Theater on Sunday night, his black-and-white-striped Beetlejuice suit enveloped by a cloud of smoke, he uttered a few special parting words:“Goooodbye, Broadway!”And he meant it.“I’m very aware that it really could be the last time I am on Broadway,” said Brightman, 35, who for parts of the past four years has played the ghostly guide to the other side in “Beetlejuice,” the Broadway musical based on the 1988 Tim Burton film about a face-off between a goth girl and a devious demon. “So it’s a humbling experience to be up there and to be able to share and be vulnerable.”After his first entrance of the final show, Brightman was met with a two-minute standing ovation.Dolly Faibyshev for The New York TimesHis farewell wasn’t quite the one he had anticipated. At a Christmas Eve performance, Brightman slammed into the show’s giant sandworm backstage at a full sprint — when a door hadn’t opened, Brightman tried an ill-fated alternate route — leaving him with a concussion.“I didn’t realize what had happened,” he said. “I figured I just banged my head.”Symptoms abruptly surfaced two days later, and after spending the next week nauseous, achy and painfully sensitive to light, he thought he’d played his final performance — maybe ever. (Three of the show’s standby and understudy Beetlejuices, Andrew Kober, Elliott Mattox and Will Blum, filled in while Brightman was out.)“I thought I wasn’t going to recover,” said Brightman, who was funny and lively in the eighth-floor cocktail lounge at the Marriott Marquis hotel before getting into costume for Sunday evening’s performance. “It felt like one long 10- or 11-day sickness in one day.”But things improved about a week ago, he said, and after doing a four-hour rehearsal on Thursday, he got the all-clear to return for the show’s final three evening performances.The 1,602 audience members at the sold-out performance on Sunday night, many of whom sported black-and-white striped suits and green wigs, showered Brightman with appreciation. (Everyone in attendance received a special Playbill with a silver sticker on the cover that read “It’s the Final Showtime.”) It started with his first entrance, when he received two minutes of applause and a standing ovation.Brightman received a Tony Award nomination in 2019 for his performance as Beetlejuice.Dolly Faibyshev for The New York Times“I’ve never had that happen before,” said Brightman, who has been in six Broadway shows, earning Tony Award nominations for his role in “Beetlejuice” and as Dewey Finn in the Andrew Lloyd Webber musical adaptation of “School of Rock.”Though “Beetlejuice” opened on Broadway at the Winter Garden Theater in April 2019 to mixed reviews (the New York Times critic Ben Brantley called it “absolutely exhausting”), it became a fan favorite — dozens of them would turn up as Lydia, the Maitlands and, of course, Beetlejuice to compete in the musical’s preshow costume contests. Still, the show was handed a closing notice in December of that year when what the Shubert Organization saw as a potentially lucrative production of “The Music Man” needed its real estate. Then the pandemic happened, and the production shuttered in March 2020.The surging sales before the closure led producers to reopen the show last year at the Marquis Theater in April. But attendance dipped again over the summer, and producers announced in October that the show would close in January after 679 performances. (A national touring production began in December, and there are also coming international versions in Brazil and Japan.)To protect his vocal cords, Brightman creates Beetlejuice’s signature gruff voice using a technique called ventricular fold phonation, in which he vibrates the cartilage in his throat.Dolly Faibyshev for The New York TimesBrightman and Elizabeth Teeter, who plays Lydia, paid tribute to the show’s fans, known as “Netherlings,” on Sunday night, holding up signs at the curtain call that read “Hey guys” and “Love you guys!”“This is a show about death that’s actually really a celebration of life,” the show’s director, Alex Timbers, said from the stage after a purple-and-green confetti storm. “And you all have given us life.”Before the show and directly afterward in his dressing room — sweaty and smiling in a white V-neck stained with green and red blotches as his team helped him remove his makeup for the final time — Brightman reflected on parting ways with the ghost with the most, the show’s fervent fan following and what’s next for him (other than, of course, sleeping).These are edited excerpts from the conversation.“This is a show about death that’s actually really a celebration of life,” said Alex Timbers, the show’s director, addressing the house on closing night. “And you all have given us life.”Dolly Faibyshev for The New York TimesYou first read the part in 2017. How are you feeling after tonight’s performance?Exhausted. It was very cathartic. I’m thrilled I got to close it after six years.Do you have any lingering effects from the concussion?I still have headaches, but they’re not pounding. I take Aleve. And my doctor said I will probably be prone to more headaches throughout the rest of my life because of it, but nothing too crazy.How important was it to you to make it back for the closing night?I’m not necessarily one of those people that believes in making that miraculous appearance at that last performance because he has to. I value my health, and I want to do more things after this. So running the risk of passing out onstage or reinjuring myself if I wasn’t ready was not in the cards.What has it been like starring in a show with such a devoted fan base?It never, ever gets old. The “Beetlejuice” fans are the warmest fans that I’ve ever encountered in the six Broadway shows I’ve done. It’s a lot of me in there, so for 1,500 people to accept my character in the show and my style of absurdity and comedy and improv is extremely cathartic and emotional.What is it like to spend so long with the same character?The last thing I want to do is be bored with anything I do, and anything this long has that danger, but this part allows me to discover new things not every night, but every minute. I have the ability to be a bit topical, a bit loose — it doesn’t feel like I’m on a track. That’s made it easy to do for six years.The show developed a devoted fan base who call themselves “Netherlings.” They frequently attended shows dressed as “Beetlejuice” characters.Dolly Faibyshev for The New York TimesWhat’s a moment that’s different in every show?There’s a part in the opening number where I have a stand mic and do a Frank Sinatra impression for a “Tip Your Waitress” kind of thing. And in it, there’s space for me to say a couple of things if I want to. The other night, I just screamed “The Kardashians!” and it got a laugh for no reason. And then right after I said, “I can’t keep up with them.” “Gangnam Style!” has also been a popular one.What did your first attempts at the Beetlejuice voice sound like?At my first audition, I was like, “I don’t know how to do a Michael Keaton impression, so let me just try something.” And it went fine, but I paid for it for two days — my voice was on fire.How do you do it now for eight shows a week without damaging your vocal cords?It’s called ventricular fold phonation, and it means you vibrate the cartilage in your throat alongside your vocal cords. I was able to figure out through trial and error that it’s the same muscles I use to clear my throat. I could do this interview better — and more healthfully —[switches to Beetlejuice voice] in this voice than just talking to you with [reverts to normal voice] this voice, because right now I’m using my vocal cords, and vocal cords get tired. Cartilage doesn’t get tired — there’s no nerves, it’s not a muscle.“This part allows me to discover new things not every night, but every minute,” Brightman said.Dolly Faibyshev for The New York TimesWhat’s next for you?I sold a cartoon series to Warner Bros., “Cleaners,” which is a raunchy, slightly musical comedy about a crew from Boston that does biohazard cleanups — crime scenes, meth labs, hoarders. And I wrote a play called “Everything Is Fine,” about the one-year aftermath of a mall shooting from the perspective of the family of the perpetrator, who is no longer with us. Cynthia Nixon directed a number of the readings, and we’re hoping to continue getting that somewhere in New York. And I’m working on a musical with Universal Theatrical with my writing partner, which is an adaptation of the film “It’s Kind of a Funny Story,” about a kid who checks himself into a psychiatric ward.So, a lot of writing.I’ve been onstage for 15 years now, kind of consistently, and I’m a little Broadway-ed and musical-ed out, which I know is a very privileged thing to say. But what comes with doing this is scrutiny. People look at you and judge you every night. I want to do my own thing for a second — to just let my work speak for itself and not have to defend it with a musical number.Would you ever want to return to “Beetlejuice”?What I know is that I have the right of first refusal for a London production, were it to happen. There are no designs for it to happen just yet that I know of, but I would consider it.“I’ve been onstage for 15 years now, kind of consistently,” Brightman said. “I want to do my own thing for a second.”Dolly Faibyshev for The New York TimesLet’s do a quick round of confirm or deny.Ooh, yes!You have done the voice in a public setting that is not the theater.Confirm. A few months ago, I went into Starbucks and said [in his Beetlejuice voice] “Can I just have one grande Pike Place with a little bit of half and half and just one Splenda?” They said, “What’s your name?” And I said [in Beetlejuice voice], “B.J.” And then they said, “Coffee for B.J.?” And I said [in Beetlejuice voice], “Thanks so much.” And I left. It’s New York. I was the least weird thing to walk into that Starbucks that day.You get nervous when you know someone famous will be at the show.Deny. The only person who would make me nervous would be Mel Brooks, because I revere him to a point that is probably pretty unhealthy.If you had to choose between marrying Beetlejuice or having to wear a single pair of used workout clothes for the rest of your life, you would —Marry Beetlejuice, if only for the fact that I know how much I sweat. More