It's official: The seven stars of BTS—J-Hope, Jin, V, Jungkook, Jimin, Suga and RM—have created an "ARMY" of worldwide fans. As they continue to break records, it's become increasingly clear that the K-pop titans are currently the most visible representatives of where mainstream pop music—American pop music in particular—is headed.

Now, K-pop itself is certainly nothing new (the genre in its contemporary form has been around since the '90s). So, what is it about BTS that has America in such a frenzy? Here are five major reasons why the seven-piece band stands apart from the pack, and why they're unlikely to slow down any time soon.

1. BTS Defy Expectations…

At first glance, and considering the industry's ebbs and flows, it might be easy to write BTS off as just another musical fad. But that would be underestimating BTS' power to connect with audiences: Not only do their steady stream of albums touch on important topics like self-love and follow a developing story arc, last year BTS packed arenas on their Love Yourself global tour. The North American leg alone, which brought the boys to eight cities, had four sold-out shows at the 21,000 capacity Staples Center in Los Angeles. And their first-ever stadium show in the U.S., at New York City's Citi Field, welcomed 40,000 loyal fans for another sold-out show.

What's more, BTS openly experiment with K-pop and boy-band aesthetics, crossing genres and subverting expectations. They defy gender norms and push aside outdated ideas of pop star masculinity via their fashion and music choices, not unlike other young, modern stars like Puerto Rican rapper Bad Bunny. In their live review, the LA Times noted BTS' "thrillingly evolved presentation of gender," with multiple costume changes, including "frilly white blouses" and "baggy tracksuits," and playful on-stage interactions

"The effect was a welcome disruption of what we expect a male heartthrob to look and sound like—a radical cultural act made only more encouraging by how enthusiastically it was received by the diverse crowd inside Staples Center," Mikael Wood, a pop music critic for the paper, wrote.

2. …And Gracefully Crosses Genres

Additionally, in his review of the NYC show, longtime New York Times pop music critic Jon Caramanica eloquently summarized how BTS' music is more than just airy takes on bubblegum pop. "Those albums [Love Yourself: Tear and Love Yourself: Answer] show how BTS navigates an increasingly variegated and complex sound: Chainsmokers-esque EDM-pop, 1990s R&B, hip-hop from New York and the South, and much more. As singers and rappers, the members are gifted. As dancers and performers, they are nimble. And at this show, their execution was relaxed," Caramanica said.

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3. All Seven Members Offer Unique Talents To The Group

At first glance, seven members may sound like a lot for a group that doesn't actively play instruments. But, as any ARMY member will be surely attest, Jin, V, Jungkook, Jimin, J-Hope, Suga and RM each play an important role in shaping who BTS are. For starters, the band splits duties between rapping and singing. And, unlike boy bands of yesteryear, there are no de facto "leaders" or frontmen. RM, who is fluent in English, often speaks on behalf of the group, but he is not necessarily the lead member.

As Caramanica also pointed out in his show review, BTS readily share the spotlight onstage, much to their fans' delight: "Near the end of the show, 'The Truth Untold' showcased the sweet harmonies of the four singers (Jimin, Jin, Jungkook and V), and was immediately followed by 'Outro: Tear,' which displayed the versatility and range of the three rappers (J-Hope, RM and Suga). Each member was given a solo turn as well — V's sensual R&B on 'Singularity' was a high point, and on 'Serendipity,' Jimin pulled off some balletic, Matrix-esque dance maneuvers."

4. Their Music Feels Authentic To Fans

While BTS have clearly mastered how to look and sound good, they do more than just draw people in with catchy hooks and eye-catching clothes and hair. They tackle important issues, like mental health and self-love. The group acknowledges the importance of serving as role models to so many young people around the world. In Korea, K-pop stars are even referred to as "idols"—and BTS don't take that responsibility lightly.

Back in Sept. 2018, the GRAMMY Museum hosted A Conversation With BTS, where 300 fans listened to the group talk about a breadth of topics, including their responsibility as artists.

"That makes us think more about our responsibilities, how we should act, how we should make our music. So it makes us think more deeply about what we do, how responsible we should be about what we're doing, and the music we're making," Jungkook said.

They also discussed their creative process and how they work collaboratively as a team, as well as with Bang Si-hyuk, the head of their label, Big Hit Entertainment. "When we had our conversation with Mr. Bang when we first started out, he always emphasized that we should sing about our own experiences, our own thoughts, our own feelings. So, that has always been at the center of the music that we made," RM explained.

He also emphasized their collaborative process as bandmates. "We try to participate together as much as we can. I think our participation in the process makes the music more sincere, make the songs more sincere, and that changes our attitude about how we approach our songs," RM said.

5. BTS Think Of Their ARMY As Family

You can't talk about BTS' record-breaking rise without also highlighting their loyal ARMY, which stands for Adorable Representative M.C. for Youth.

In fact, BTS has two official Twitter accounts: At the time of this writing, @BTS_twt is home to 18.5 million followers. The ARMY is very active on the platform, as evidenced by one unoffical ARMY account having sent out a fervent 116k tweets to date. Additionally, BTS' official YouTube page has over 15.6 million subscribers.

Yet just as fans support BTS, BTS supports their fans. All in their mid-to-early-20s, the members of BTS know how to use social media as a tool to connect with their millions of admirers online, giving fans regular access and updates on their lives. While many social-media users at risk of falling into feelings of isolation the more they "like" and scroll, BTS actively leverage positivity on social media. Fans follow suit, filling BTS' YouTube page with upbeat, supportive chatter. Together with their fans, BTS creates a giant, supportive family.

And the BTS U.S. takeover is only just getting started: Following the announcement of BTS' new 2019 tour dates, fans took to Twitter to share in the excitement, with some wondering if this was how their parents felt when The Beatles toured. Others pointed out the significance of some of the venues: For example, the Rose Bowl in Pasadena, where BTS will be performing on May 4, is a football stadium with a capacity of 90,888. Rose Bowl concerts are reserved for the likes of the Rolling Stones and Beyoncé and Jay-Z, who brought their OTR II tour for two nights to the huge venue last September.

The numbers don't lie: Between record and ticket sales, streaming numbers, self-aware lyrics and a fervent fan base, BTS have tapped into a formula for history-making success—in America and all over the world.

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