Cameron Mackintosh is one of the longest-running producers of all time with a roster of hits, including “Cats,” Les Miserables” and “The Phantom of the Opera.” (Simone Massoni for The Washington Post)

NEW YORK — When Cameron Mackintosh speaks in those plush English vowels about his latest old-made-new venture on Broadway, you almost feel as though you’re listening to words that were meant to be inscribed on tablets.

“She is a stahhh!” he is saying, with the easygoing authority that comes naturally to a born showman. “You could tell she was a stahhh. You could see there was something there. It was the same as with Lea. You knew. And how extraordinary God would give us two 17-year-olds who are sensational.”

Producer Cameron Mackintosh. (Michael Loccisano/Getty Images)

He is sitting in the offices he has long occupied in the middle of the theater district, heaping Mackintoshian enthusiasm on the casting coup he thinks he has scored for the new revival of “Miss Saigon,” which has its official opening March 23 and is the latest of Mackintosh’s ’80s and ’90s megahits to return to Times Square. The major discovery the first time around for “Miss Saigon” was Lea Salonga, a teenager from the Philippines with a voice like liquid gold, and Mackintosh is certain that his new Kim, Eva Noblezada, is another teenage sensation.  

“You just know,” he says, “that they have some innate stillness in them that makes you go, ‘They need to be up there.’ ”

Audiences know, too, that with his list of hits on both sides of the Atlantic — among them “Cats,” “Les Miserables” and the longest-running Broadway musical of all time, “The Phantom of the Opera” — the 70-year-old Mackintosh also is one of the most successful and longest-running producers of all time: His first producing credit came in London 50 years ago, at age 20. But it’s also clear, as Mackintosh prepares to accept an award Monday night from Signature Theatre, the company’s Sondheim Award — named for the revered composer-lyricist and bestowed annually on a figure chosen in consultation with Stephen Sondheim himself — that the era in which he reigned supreme is drawing to a close.

From lef to right: Steve Barton, Michael Crawford and Sarah Brightman take a bow during the curtain call at the end of the 1988 premiere performance of “The Phantom of the Opera” in New York. (Ed Bailey/AP)

The megamusical is not yet down for the count: “Phantom,” which has been at New York’s Majestic Theatre since 1988, has passed the 12,000th-performance mark, and “Les Miz” has been to Broadway three times since 1987 under Mackintosh’s auspices, the last go-round ending in 2016. His Midas touch with mass-appeal musicals worked again in the 2000s with “Mary Poppins,” which he produced with Disney Theatrical Productions. And tours of his major successes — shows that essentially rescued “the road” from oblivion — are still huge draws across the Americas, Asia and Europe: A new “Les Miserables” company goes out on the U.S. circuit in the fall, and a new “Miss Saigon” the next year.

Actress-singer Betty Buckley performs in the role of Grizabella in the Broadway musical "Cats" in 1983. (Richard Drew/AP)

Mackintosh’s sometime partner, Andrew Lloyd Webber, has four shows on Broadway at the moment, including a relatively new one, “School of Rock — The Musical,” so it would be hard to argue for the irrelevance of British theater royalty. Still, Mackintosh is enough of a student of theater trends — heck, no one reads them, even now, better than he — to understand that he’s not in the vanguard anymore. “This particular cycle is over,” he told London’s Telegraph in 2014. “What it needs is a new Cameron Mackintosh, to come up and work with a younger generation.”

The kind of spectacle of which he has been the champion — musical epics framed by war and love, stories featuring flying chandeliers, flying helicopters and flying nannies — are no longer the artistic vogue. The only thing flying at “Hamilton” is money into the box office. The new musicals making a mark this season, “Dear Evan Hansen,”Natasha, Pierre and the Great Comet of 1812” and “Come From Away” on Broadway and “The Band’s Visit” off-Broadway, are quirkier pieces, by a mostly younger cadre of composers, book writers and lyricists, whose ideas for the form are driven more by the dictates of intimacy and new musical styles than by pyrotechnics. (Let’s stipulate that the scores of “Les Miz” and “Miss Saigon” at times also set off their own melodic fireworks.)

"Les Miserables" by Cameron Mackintosh, as seen at the Paper Mill Playhouse in 2010. (Deen van Meer)

The producer is still able to hit the jackpot, though, with emergent power players such as Lin-Manuel Miranda: One of the eight theaters Mackintosh owns in London’s West End, the Victoria Palace, is being renovated for the November opening of the London production of “Hamilton.” Inking a deal with that musical amounts to seizing the Holy Grail; the entire first tranch of tickets sold out in 48 hours. “I’ve never known that kind of intensity,” Mackintosh says. “Ever.” True to his restless reputation, the impresario is introducing front-of-house innovations, such as a paperless ticketing system for “Hamilton,” which he thinks will help thwart scalpers and revolutionize the theater business.

Of late, his concession to changing musical tastes has been to polish old gems rather than cut new ones. “That’s why I’ve done the new ‘Phantom,’ ” Mackintosh says, about a recent refreshing of that show that “evolved out of necessity and boredom.”

Eva Noblezada, left, and Alistair Brammer in the musical "Miss Saigon" in London, 2014. (Matt Dunham/AP)

“Because it’s interesting to do something new after 25 years,” he adds. “I mean, I’m very proud of the original productions — it’s great material. And like any great material, you want new generations to bring their imaginations.”

To those who have worked with and for him, including Eric Schaeffer, Signature’s artistic director, Mackintosh’s staying power after half a century, his ability to remain so exuberant, is a testimonial in itself.

“In those 50 years his passion hasn’t diminished,” says Schaeffer, who directed an original musical, “The Witches of Eastwick,” for Mackintosh in London. “It’s just grown and grown and grown.”

Mackintosh says that he is “not an awards person” and that he tends not to attend trophy ceremonies. But the Sondheim Award is one of the exceptions: “Because it’s Steve, him wanting me to do this,” he explains. “The two I’ve really enjoyed are the Richard Rodgers [Award] in Pittsburgh” — given for excellence in musical theater — “and this one from Steve. Two of my greatest heroes.”

That they are accolades bestowed by American organizations speaks to the profound affection Mackintosh has long felt for the theater industry in this country, where, he says, he was embraced at a tender age. For all the success of the shows he has produced by Lloyd Webber (“Cats,” “Phantom,” etc.) and the French team of Claude-Michel Schonberg and Alain Boublil (“Les Miserables,” “Miss Saigon”), musicals are an American phenomenon. And from his earliest days in the theater, Mackintosh was interested in putting American material on the London stage. It was a Sondheim revue, “Side by Side by Sondheim,” he produced in 1976 at Wyndham’s Theatre just off Leicester Square — a theater he would one day buy — that amounted to his first British export, although he didn’t retain the rights when it moved to Broadway.

“Everyone has been in­cred­ibly welcoming to me ever since I was penniless when I came here in 1976,” he says. “I never ever had anyone not be encouraging to me in this country.” Bernard Jacobs, then the artistic brain behind Broadway’s biggest theater owner, the Shubert Organization, would give him an apartment in New York to stay in. And one day in Washington almost 40 years ago, after Mackintosh had seen a tryout of David Merrick’s “42nd Street,” he ventured over to the Watergate and rang up the storied producer in his room.

“I said, ‘Hi, David, it’s Cameron. You met me once when I did “The Card” in London. I just wanted to say the show was brilliant, and if there’s anything I can ever do for you for the show . . .’ And he went, ‘Wait there.’ Ten minutes later he came down and gave me the most extraordinary master class, for two hours.”

Mackintosh recalls with great warmth theater figures of Jacobs’s and Merrick’s stature, and, like them, he has had his misses, as well as triumphs: In 1996, Boublil and Schonberg’s “Martin Guerre” — another lavish stage musical, based on the story recounted in the 1982 movie “The Return of Martin Guerre” with Gerard Depardieu — was met with mostly negative reviews in London. At the time, Mackintosh noted that a decade earlier, “Les Miz” had not been embraced by the London critics either. Ultimately, “Guerre” was seen as a defeat; it never made it to Broadway.

The return of “Miss Saigon,” though, has reunited the producer with one of his favorite properties. Its initial Broadway run (4,092 performances, 1991-2001) was spectacular by any other measure than a Mackintosh yardstick. The subject of the Vietnam War had narrowed the family-viewing pool somewhat: “You need to take 10- to 12-year-olds, not the 6- to 8-year-olds who can sit through ‘Les Miz’ or ‘Phantom,’ ” he says. This is partly why the run of this “Miss Saigon” is being advertised as “limited” through January 2018 rather than open-ended.

But if it catches fire, who knows? Mackintosh waxes poetic about the actors he has found who are making their Broadway debuts, such as Jon Jon Briones, playing the bravura role of the shady Engineer, originated on Broadway by the Tony-winning Jonathan Pryce. The story, he says, has never been more relevant, telling of a young Vietnamese woman who falls in love with an American G.I. and is left behind with their child after the fall of Saigon.

“The sad truth is that the world has caught up with ‘Miss Saigon.’ You’ve got the refugees; they’re climbing over the walls,” Mackintosh says, referring to the famous scene re-created in the musical when the gates of the American Embassy closed, shutting out the Vietnamese desperate for a spot on one of the evacuation helicopters.

The discussion reminds him of how contemporary politics plays into his hands, even in a piece depicting earlier history, such as “Les Miserables,” with its depiction of the barricades during the Paris uprising of 1832. “What’s going to happen when we do it in Mexico?” he asks. “I think I just have to raise the Mexican flag during ‘One Day More,’ and the audience will give it a standing ovation! I have to send a thank you to the Donald, for making all my shows so current.”

But wait! Back to “Miss Saigon,” please. Inquiring minds want to know:

The helicopter that swooped out of the rafters so famously in the original? Is it back?

A laugh erupts from the perpetual showman’s gut.

“Bigger,” he exclaims, “and better than ever!”

Correction: An earlier version of this story misidentified the nationality of Eva Noblezada. She is American.