On February 13 of this year, the Montreal rock band Arcade Fire, known for their spirited live shows and ragged emotionalism, arrived at the Grammy Awards with low expectations. Their third LP, The Suburbs, released on the independent label Merge, was inexplicably nominated for album of the year, up against efforts from four of the biggest acts on the planet: Lady Gaga, Eminem, Lady Antebellum, and Katy Perry. The past decade has been hard on the music industry, but the Grammys have generally been content to go down with the ship, doling out prizes in accordance with establishment tastes. Few expected a bunch of shabbily dressed Canadians to beat out the luminaries who brought us “Poker Face” and “I Kissed a Girl.”

As the ceremony dragged on, the band performed “Month of May,” one of The Suburbs’ harshest songs — a thumbed nose at the Grammy overlords. Then Barbra Streisand took to the podium and announced the winner: “The S-s-suburbs?” The band members themselves were as shocked as the rest of the universe, beaming adorably as they thanked Montreal for giving them a musical home. “We’re going to go play another song,” singer Win Butler announced, between bleeped expletives, ” ‘cause we like music.” Then they launched into the tough, terse “Ready to Start,” whose lyrics describe businessmen drinking blood, and the emperor’s new clothes; if this was another protest song, though, why did the band members look so giddy?

Almost immediately, furious people took to Twitter, as furious people do these days, to register their disgust. “Fuck the fucking grammys!!!” went one typical response. “I cant see wat im typing but fuck those mother fuckers!!! Arcade fire?!! Who the fuck arfe they? I dnt know…” Rosie O’Donnell (“album of the year ? ummm never heard of them ever”) and Dog the Bounty Hunter (“Who the he’ll is that Fire who?”) both tweeted their displeasure; the whole firestorm was documented on a sarcastic Tumblr titled “Who Is Arcade Fire??!!?” The band members took it in stride: “We’re called Arcade Fire,” Butler later joked at the Brit Awards, in a nod to the meme. “Check it out on Google.”

But no one was more surprised than Arcade Fire’s fans, some of whom had been following the group since it formed ten years ago, in the living rooms and underground venues of Montreal. “It has been almost a decade since I first heard Win’s voice, plaintive and twanging, at a Battle of the Bands,” wrote Sean Michaels the next day, on his influential music blog, Said the Gramophone. “They have come a very, very long way, mostly just by playing their hearts out.” In the process of achieving incredible success, Arcade Fire almost single-handedly turned the world’s attention to Montreal’s music scene, and became the ultimate contradiction: an indie rock band that sells millions of records and racks up major awards. How did this happen?

Win Butler and Régine Chassagne’s first date was also their first jam session. They initially met at McGill University, where she sang jazz while he, a religious studies student, stalked the music department’s halls, hassling other students to start a band with him. But the two did not stumble upon their trademark synthesis — his quivering Americana tenor paired with her technical prowess and sense of whimsy — until they bumped into each other at an art opening. That night, in Butler’s apartment, the pair wrote “Headlights Look like Diamonds,” which would eventually appear on Arcade Fire’s debut EP. “The countryside’s deserted / there’s no one on the farms,” Butler croons; perhaps not a terribly romantic tune, but when was the last time you composed a song on a first date?

At the time, Montreal was not quite the indie rock mecca we know today. It had a rich history — jazz in the ’60s, punk in the ’70s, new wave in the ’80s — but around 2001, widespread pay-to-play policies discouraged live music in bars, and the city’s best-known band was the sombre, instrumental Godspeed You! Black Emperor. Over the next several years, as Arcade Fire performed in lofts and galleries, supported by a rotating cast of local musicians, it gained a reputation as a formidable live act. (Chassagne and Butler married in 2003.) This was a very different time in music: the terms “hipster” and “indie rock” still brought to mind beat poets and ’90s alternative acts like Pavement. Today, fairly or unfairly, these are almost always labels of derision, connoting fleeting musical trends and pretentious Brooklynites in skinny jeans.

I first saw Arcade Fire during this in-between period, in the summer of 2004, at a small folk festival in Ontario. They opened with “Wake Up,” still arguably their best live song: the anxious, wordless oh-oh-oh chorus, their collective voices cracking on that high A. They wore frayed dresses and ties, like aristocrats fallen on hard times, and the music they played was soaring, almost spiritual. A few months later, I moved to Montreal, and Funeral, their massive debut, dropped like an anvil. I bought it in a now-defunct record store on Ste. Catherine Street, popped the CD into my Discman (a more obsolete collection of words I cannot imagine), and listened to it in the autumn chill as I trudged back to campus. Within a year, the record sold half a million copies. Arcade Fire opened for U2, played with David Bowie, and appeared on the cover of Time Canada.

By 2005, as the group drew more attention to the town from which it sprang, the trend-hungry New York Times was declaring Montreal an “It City,” on par with Seattle during the grunge era. That same year, the music outlet Pitchfork, whose name has become synonymous with indie, ran an interview with the band. “It’s pretty weird that we keep getting tied together in the press,” the writer said, by way of a question. “Like, a lot of the features I’ve read on the Arcade Fire mention Pitchfork and vice versa.” This was a sly ruse, a way for the website to point up its burgeoning influence while distancing itself from accusations that it was perpetuating an unsustainable hype cycle. Although its early, glowing review of Funeral is frequently credited for Arcade Fire’s success, the effect went two ways: the band’s rise also cemented Pitchfork’s status as this generation’s most definitive tastemaker. Arcade Fire’s members were standard-bearers who represented not just Montreal’s musical ascension, but that of an entire subculture.

The wave of indie rock they led arose while the music industry was entering a period of great turmoil. In the early 2000s, file sharing demolished the major label business model, while independent labels and bands — with their loyal fan bases, dedication to touring, and grasp of the Internet’s marketing potential — weathered the storm. The indie scene’s newfound viability allowed Arcade Fire to retain its autonomy by sticking with Merge, even though it seemed primed for a major label. As a result, it’s not quite as popular as a star like Katy Perry, whose Teenage Dream has sold 1.7 million copies; The Suburbs has sold almost 500,000 to date. But recall that Britney Spears’s …Baby One More Time, from 1999, reportedly sold an absurd 25 million units. The digital revolution effectively levelled the musical playing field, allowing Arcade Fire to come closer to the pop mainstream than any independent band before it.

“Indie rock” is a woolly term; it stands for a music defined by its ethos rather than its sound. One could say the same about punk, but indie’s sonic diversity is unprecedented: it can encompass both an unlistenable noise act and an acoustic singer-songwriter. Arcade Fire has always been a pop band, though. It just took us ten-odd years to realize it. Funeral is full of big hooks and proper choruses, and it’s undoubtedly one of the most influential albums of the decade, having inspired legions of indie rock clichés: earnest group vocals, boots-and-pants beats, the use of once-unusual instruments like the accordion and the xylophone. On Neon Bible, its second album, and The Suburbs, Butler’s voice is raised considerably in the mix, and the production is more polished, giving the records a classic rock feel.