Throw Up Your Hands and Raise Your Voice! Monorail! Monorail! Monorail!

Driving home one day in the early ’90s, Conan O’Brien found himself in a familiar situation: alone in his car, laughing. He had spotted a billboard that he’d never seen before. He doesn’t remember the exact details of it, but one word stuck out: “It just said ‘monorail.’ I don’t even know why.”

This giant advertisement was completely inexplicable, yet O’Brien also saw it as a perfect joke on itself. “Monorails were always funny to me because they’re a phony promise of the future,” he says. “It really is just a trolley, right?”

The young Simpsons writer pitched a story about the newfangled mode of travel, which soon turned into one of the best sitcom episodes of all time. “Marge vs. the Monorail,” which aired 30 years ago this month, warned the world about charismatic men selling foolishly grandiose solutions to problems that don’t need fixing. It tells the story of a charming man named Lyle Lanley who blows into town and convinces a cash-flush Springfield to build a train that “glides as softly as a cloud.” Naturally, though, he’s a scammer. And soon after his shiny but janky system opens, “it all goes to shit,” as O’Brien puts it.

The episode was the first true extravaganza for a groundbreaking animated series that was originally conceived as an intimate family comedy. Both visually and narratively, it was an installment that expanded the world of The Simpsons as it moved beyond its first few seasons. All the quotable lines, sight gags, pop culture references, ambitious set pieces, and catchy songs add up to something unexpectedly (and eternally) prescient. The episode is now synonymous with modern hucksterism: Whenever a fancy new transportation system, or a billion-dollar eyesore, or a deal that enriches corporate executives and few others comes along, it can’t escape comparisons to Lanley’s genuine, bona fide, electrified, six-car monorail. “I get a kick out of the cultural reach of The Simpsons,” says television writer and producer Jeff Martin, who had a hand in making “Marge vs. the Monorail.” “Now if there’s some shorthand for a dishonest salesman, a flimflam man, it’s a monorail salesman.”

O’Brien didn’t expect the episode to live on like it has. “If you could have told 28-year-old Conan, ‘I know you’re driving a Ford Taurus, and it’s really cold in your office, oddly, on the Fox lot, and it’s raining out and you’re here on a Saturday, and then you drive to a Chinese restaurant on the way home and eat alone at a table and continue to scratch away at your legal pad, [that] someday you’ll be performing a piece of this episode at the Hollywood Bowl,’” he says. “If you told me that, I still, as I’m saying this to you—my mind can’t contain those two things.”

Growing up in Brookline, Massachusetts, O’Brien developed two lifelong obsessions. The first was The Music Man. Based on Meredith Willson’s hit Broadway musical, the 1962 film stars Robert Preston as con man Harold Hill, who poses as a marching band instructor in an attempt to bilk the unsuspecting citizens of River City, Iowa. After O’Brien heard Preston’s showstopping song “Ya Got Trouble” for the first time, it wormed its way into his brain. “I always wanted to play the Robert Preston part and do the ‘Trouble’ song,” he says. “I just love the ‘Trouble’ song.”

O’Brien’s other fixation was the work of filmmaker Irwin Allen, who produced disaster movies like The Poseidon Adventure and The Towering Inferno. They all stuck to a specific formula, and they were all entertaining as hell. “The beginning is always great promise,” O’Brien says. “‘We built this wonderful skyscraper!’ There’s a lot of talk about the skyscraper, and then there’s always a dire warning: ‘You should worry about the electrical system and the smoke alarms.’ Don’t you worry about that! Then, there always comes the moment where all the celebrities are being brought in for the big grand opening.”

Then, it all goes to shit.

“Somehow, all those things are swimming around in my head,” O’Brien says. It just took a space-age train to bring them together. “It unfolds really naturally because once you have the idea of a Music Man selling you a monorail, you know Homer’s for it, the town’s for it. … Well, who’s going to be against it? It’s either Marge or Lisa, because they’re sensible. For me, it was Marge. She’ll be the voice of reason who senses this isn’t wise. The first part is Music Man. The second act is an Irwin Allen disaster movie.”

O’Brien loved his premise. He just wasn’t sure that his colleagues would. But when he ran it by showrunners Mike Reiss and Al Jean, they laughed. He kept it in his pocket until a staff story retreat, where writers pitched executive producer James L. Brooks. If Brooks liked an idea, someone in the hotel room where they gathered banged a gong. “I pitch an idea,” O’Brien says, recalling himself as the skinny new guy with a big mop of red hair. “James L. Brooks has a very distinctive laugh. He starts laughing. … Gong. Then I pitched the second idea. That went well and that got gonged. There was part of me that thought, ‘Get out now while you’re ahead.’”

Then, O’Brien remembers Jean chiming in with, “Tell him about the monorail.”

“I was thinking, ‘Eh,’” O’Brien says. “Then, I thought, ‘Well, you’ve got two, so why not? The pressure’s off.’ I’m glad it wasn’t my first pitch, but I pitch it.” Sure enough, Brooks laughed. Then: gong. “From that moment on, that was the one I wanted to write,” O’Brien says. “I just wanted to write the monorail.”

While “Marge vs. the Monorail” reflected O’Brien’s comedic style, making it was, like all Simpsons classics, a group effort. “The part that needs to be stressed is that I thought I had a good outline for an idea and good stuff there. Then, suddenly you’re in a room with [John] Swartzwelder, and [Jon] Vitti, and George Meyer, and Jay Kogen, and Wally Wolodarsky, and Jeff Martin. Reiss and Jean. Everybody’s throwing in great stuff,” he says. “That’s the part of that show that I think was so magical: Everybody comes together in this very communal way. This was interesting to me because I had come from SNL, where you work on your own sketch. … It’s much more competitive.”

When it came time to write his version of “Ya Got Trouble,” O’Brien went to a Los Angeles library and checked out The Music Man soundtrack on vinyl. He listened to it with Martin, his friend since their Harvard Lampoon days. “We knew that it had to have that kind of feel,” O’Brien says.

Martin recalls O’Brien stopping by his office to share lyrics that he’d come up with, like this exchange with Grampa Simpson and Lanley:

“Were you sent here by the devil?”
“No, good sir, I’m on the level.”

“He just knew he had something good,” says Martin, a prolific Simpsons songwriter who helped come up with the propulsively simple tune to accompany O’Brien’s words. “It’s like, ‘Boom, boom, boom, boom, done.’”

“The Monorail Song,” which Lyle Lanley uses to convince Springfield to invest in a shiny new train line and not in rehabilitating its badly damaged Main Street, is the episode’s showstopper. And there was no one better to sing it than Phil Hartman, a versatile voice who’d already shown a knack for playing charlatans like the Hollywood has-been Troy McClure and the sleazy lawyer Lionel Hutz. “One of the things that he did particularly well was bravado and confidence,” says O’Brien, who’d known Hartman since their time together on Saturday Night Live. “I remember when I’d see him at SNL, if he walked into a room and he saw me sitting with Greg Daniels and Robert Smigel and Bob Odenkirk, he’d say, ‘Hiya, fellas.’ We’d say, ‘Hi, Phil.’ He’d go, ‘Keep them flying, boys. Keep them flying, and keep walking.’ It was a breezy, self-assured, slick, confident guy.”

Like Hartman, Lanley was hypnotically self-assured. Nothing seemed to affect him. “You realize, yeah, Phil could have been the star of The Music Man,” O’Brien says, “and he would’ve killed it.”

In addition to a charismatic villain, the “Marge vs. the Monorail” writers wanted a guest star whom they associated with the future. Originally, that was supposed to be George Takei, who played Sulu on Star Trek. But he turned down the offer to appear as the grand marshal of the Springfield monorail’s opening celebration.

“We were all stunned,” O’Brien says. “‘What do you mean George Takei said no?!’ I didn’t know what he was doing at the time. Then it came back to us that George Takei was somehow affiliated with the San Francisco Board of Transportation. He thought that this was maybe making fun of public transportation.”

The next day, O’Brien’s boss cheered him up. “I’m walking by Al Jean’s office and he says, ‘Leonard Nimoy said he’d do it,’” O’Brien recalls. “I said, ‘What? That’s better. He outranked Sulu. This is great.’”

Getting to work with Spock himself brought O’Brien back to his childhood. “Lying on the floor in my parents’ living room, watching endless reruns in the dreary Boston ’70s, and here he is,” he says. “That was electric. He didn’t have many lines, but I got to be in the studio when he did it, which was one of the joys of my life. I don’t care how many famous people you get to meet in this life, it’s seeing the people you grew up with on television in real life that trumps everything.”

By then, O’Brien had started to imagine what the episode might look like. Director Rich Moore, supervising director David Silverman, and the show’s animators had no template for such an ambitious project but relished the challenge of spending hours creating the set of an action movie from scratch, complete with a working transportation system.

“I felt like, ‘Oh, this is such a me kind of idea that I had an ego about. I really hope this gets done, I’m very excited to see it if I can, and what’s the monorail going to look like?’” O’Brien says. “I couldn’t believe this could really happen.”

On January 14, 1993, midway through the spectacular fourth season of The Simpsons, Fox broadcast “Marge vs. the Monorail.” It was exactly as offbeat as O’Brien envisioned it: The opening gag, a Homer-sung parody of The Flintstones theme song that executive producer Sam Simon suggested, has absolutely nothing to do with the plot—and from there the episode becomes more and more madcap.

After Mr. Burns is fined $3 million for dumping nuclear waste in a park, there’s a town meeting about how to spend the money. Then comes “The Monorail Song,” featuring a call and response between Lanley and Springfield citizens curious about the transportation system. Even its most meaningless line—“Wiggum is like, ‘The ring came off my pudding can,’ which has nothing to do with what everyone else is asking questions about,” O’Brien says—is funny.

Eventually, Marge’s detective work exposes Lanley as a fraud and his monorail system as a lemon with faulty brakes. But not before the Irwin Allen disaster movie portion of the program begins. Homer, the newly hired conductor who befriends a family of possums living in the cockpit, saves the day by using a donut shop sign as an anchor. In a sign that The Simpsons had begun to fully embrace the surreal, Nimoy leaves the scene by beaming out.

Soon, O’Brien left Springfield, too. That spring, NBC hired him to host Late Night. “At some point, a giant tidal wave washed me away from Simpsons-land,” O’Brien says. “I was totally immersed in this other world and all these problems and in the fight of my life to try to get my late-night show up and running—and survive.”

Yet “Marge vs. the Monorail” followed O’Brien across the country, from L.A., to Brockway, to Ogdenville, to North Haverbrook, to New York City. “I remember an early fan who would hang around Rockefeller Center wore a handmade jacket that had the monorail on it,” he says. “That gave me some solace. No one else in America knows who I am. They’re not too happy with me, I don’t think at this moment, as David Letterman’s replacement. But here’s a fan who’s maybe only checking out the Late Night show because they like the monorail episode.”

Even after a late-night run that spread across networks and decades, O’Brien has never hopped off the monorail. In 2014, Jean called and said that creator Matt Groening and Brooks wanted him to step in for the late Hartman and sing “The Monorail Song” with the Gay Men’s Chorus of Los Angeles at The Simpsons Take the Bowl. “Well, there’s only one answer to that,” O’Brien says, “which is yes.”

References to the episode will never cease making O’Brien happy. While browsing the Rose Bowl flea market, his friend once noticed a framed travel poster showcasing Homer and the monorail. “It says, ‘Glides as smoothly as a cloud,’” O’Brien says. “I was like, ‘You have to buy that for me.’ It wasn’t even that much. That’s hanging in my house, and I kind of smile every time I see it.”

Still, the fact that “Marge vs. the Monorail” is seemingly brought up whenever a grifter dupes the public surprises O’Brien. After all, it was an idea that started very, very small.

During a recent visit to Massachusetts, he came across some boxes that he’d had shipped from his L.A. apartment to his parents’ house after landing the Late Night gig back in 1993. “They’re time capsules,” he says. “I opened these things up and I’m scrounging around.” Inside one of them, he found a legal pad from his Simpsons years. Halfway down the first page, there was one scribbled word:

“Monorail!”