No job in the theater lasts forever. At "The Phantom of the Opera," it only seems that way.

On Monday, Jan. 9, the Andrew Lloyd Webber musical — with performance number 7,486 — becomes the longest running show in Broadway history, surpassing another of the British composer's megahits, "Cats." And while statistics can be trotted out extolling the longevity and profitability of the production, it's the people, both on-stage and behind the scenes, who make the musical work at each performance.

Some have been there from the very beginning: Jan. 26, 1988, when "Phantom," the tale of a deformed composer haunting the Paris Opera House and his love for the beautiful soprano Christine, first opened at the Majestic Theatre.

Among those on Broadway who have found steady employment for nearly two decades are musician Lowell Jay Hershey, who plays the trumpet in the show's orchestra; Thelma Pollard, the musical's makeup supervisor; and George Lee Andrews, one of three actors who have been in the production ever since the curtain first went up in New York.

Why have they stayed so long in "Phantom"? It's good, steady work, they say.

In a career that has spanned over 30 years, Hershey has done other successful musicals, including "Big River" and "Nine," but it was the trumpet player's experiences in such short-lived duds as "Rockabye Hamlet" and "The Three Musketeers" that made him realize, "There is not really much advantage in leaving a hit show."

And "Phantom" has been among the biggest. The money it has made, not to mention the other numbers accumulated during its long run, has been staggering. Its gross in New York alone has been nearly $600 million. Almost 11 million people have trooped into the Majestic, one of Broadway's prime houses — home in the past to such legendary musicals as "South Pacific" and "The Music Man" — to see the show.

And that doesn't take into account foreign companies, including the original London version, which opened in October 1986 and is still running.

Pollard still has memories of that magical opening night nearly 18 years ago — she was able to go out into the house and watch bits of the performance in-between her cues backstage.

"I was in awe," she says. "Even before the curtain went up, we could hear the buzz of the audience on the monitors backstage. During the show, they applauded everything. And when you hear applause like that, you know it's going to be a great night."

In 1988, the New York production cost a then-record $8 million. Today, the figure would be $12 million. "Phantom" won seven Tony Awards, including the best-musical prize as well as the Tony for its original star, Michael Crawford.

Ten actors have followed Crawford as the title character, including Howard McGillin, now in his second stint in the show. McGillin has put on that mask in more than 1,400 performances, more than any other Phantom on Broadway. He'll play the role Monday at a special 6:30 p.m. performance, which will be followed by a lavish masked ball at the WaldorfAstoria hotel, presided over by producer Cameron Mackintosh.

Mackintosh is producer of the top three longest running shows on Broadway — with "Les Miserables," holding third place. Worldwide grosses have topped an astonishing $3.2 billion.

Pollard started in the show's hair department, working on several characters including Raoul, the dashing young hero who wins Christine's heart. When Tiffany Hicks, the makeup artist who came over from England to work with Crawford, left, Pollard took over — and has worked with every Phantom since then, including Crawford. All have sat in a barber chair in the star dressing room, waiting patiently while Pollard creates the Phantom's intricate facial deformity, hidden for much of the evening beneath a ghostly mask.

It originally took her one hour and 20 minutes to complete the transformation; now she does it in an hour. her workday usually begins at 6:30 p.m. — one of her three assistants does the matinees — and ends around 11 p.m. She remains on duty during the show for touchups — actors do perspire — and helps with makeup removal after the curtain comes down.

As the "Phantom" empire grew in North America, Pollard was hired as makeup production supervisor for all its companies. She went out on the road to teach other makeup artists.

But her work in the Broadway production has had other challenges, like the time she dropped one of the Phantom's wigs in the dark recesses of backstage near the end of a performance and frantically had to depend on a stagehand to climb down a ladder and recover it.

"The wig flew out of my hand and into the basement," she says with a sigh. "We have two wigs in case something happens but at the end of the show you don't want to take the wig for tomorrow and put it on the actor."

Andrews, a theater veteran of such musicals as "A Little Night Music" and "On the Twentieth Century," was 45 by the time he got to the show.

"I had had a big career, a lot of traveling, and I had a family, a daughter 10 and a son, 6," the actor says. "My original idea was to stay a couple of years."

He started as a member of the ensemble and later moved into other roles — the two managers of the opera house haunted by the Phantom.

Hershey has a great admiration for the score, particularly David Cullen's orchestrations, which are played by 27 musicians.

"The musical uses the trumpet the way it's supposed to be used," Hershey says, and he's kept busy during the performance. He did one musical a number of years ago where he had so little to do that he says he would "have to go home and practice an enormous amount just to keep my chops up. It's a physical thing and you have to stay in shape."

And like Pollard, both Andrews and Hershey have tales of mishaps. Hershey remembers one performance when music for the third violinist accidentally was left on the show's most famous prop — the chandelier.

Andrews has had to sidestep a few open on-stage trap doors in his time. And in his big letter-reading scene — there are several during the show — he's sometimes gotten the wrong letter and has had to pretend to be reading while trying to remember what the letter said. "It's a concentration thing," he says drily.

About five years ago, there was some uncertainty that "Phantom" would ever catch "Cats." Plans were being formulated for what was to be a final year on Broadway. But before that was to happen, another ad campaign was put into place, according to Nancy Coyne, chief executive officer of Serino, Coyne, which handles advertising for the musical.

"The campaign was `Remember Your First Time,'" Coyne recalls. "The specific strategy was to find out how many times people would go back. We knew they were going back two or three. We thought, `Can we get people who have been going back two or three times and push them into three or four?'"

Coyne did print ads and billboards and taped radio interviews in front of the theater.

"That's when I found out people weren't going three or four times. They were going 10 or 12 times," she says. "I had people saying, `Well it's our song. They played it at our wedding. We go every year on our anniversary.'

"That affection by the return customers was so strong that we did two radio spots with just them talking and the (box-office) figures started to build."

The climb continued with release of the movie in December 2004 and later when the film's DVD came out. Advertisements for both helped the stage version, reminding would-be theatergoers that the show was still around and turning January 2005 into the best January for grosses "Phantom" has had in the last 10 years, Coyne says.

And 2005 has turned out to be the highest-grossing year ever for the musical. Admittedly, ticket prices are higher: The top ticket price in 1988 was $50; today it is $100. For the week ending Dec. 31, "Phantom" took in $1.3 million for nine (rather than the usual eight) performances — a house record at the Majestic.

Yet what has kept Andrews, Pollard, Hershey and others employed has been more than a paycheck.

"I've always approached working each night as trying to improve it, to do the show better," Andrews says. "And there are variables. The audience is different every night. ... The show is different every night, too.

"You have to put your concentration into enjoying the show, having fun with it. ... It would be very tedious to be in a show that you had to drag along. But this show really pays off every night."