Athletic wear, leather, bandannas: The gentlemen of BTS look like they stepped out of a Y2K music video. But no, the seven members of BTS, the highest-charting Korean boy band of all time, dwell firmly in 2017. They are the face not just of modern Korean pop, or K-pop, but of popular music in the global internet era.

BTS consists of rappers Rap Monster (Kim Namjoon), Suga (Min Yoongi) and J-Hope (Jung Hoseok), and vocalists Jin (Kim Seokjin), Jimin (Park Jimin), V (Kim Taehyung) and Jungkook (Jeon Jungkook). The group combines high-quality productions, light hip-hop, sweet teen croonings and impassioned portraits of millennial frustrations. “Who made us a study machine?” they ask in “N.O,” a critique of Korea’s competitive education culture. In “Danger,” they sing, “Where did my exciting love story go? Move out of the way, [TV] drama characters.”

At their inception in 2013, BTS — whose English name is an acronym for “Bangtan Sonyeondan,” or Bulletproof Boy Scouts — didn’t have much impact on the crowded K-pop world. Instead, in a rarity for a K-pop group, they caught the ears of international fans before winning over fans at home. “We thought it was a little odd,” reflects rapper Suga, whose charcoal hair and sharp gaze lend him a solemn vibe. But this was the year after PSY’s viral YouTube hit “Gangnam Style” broke into the West. BTS’ boom was “a matter of right time, right place,” says Jakob Dorof, a Seoul-based music critic. Global audiences consumed them via social media, appreciating what Suk-Young Kim, a K-pop expert and professor at the University of California, Los Angeles, calls “a kind of authenticity.” She adds that “their lyrics are so close to reality,” discussing angst about careers, school and love. It helps that all of the members have production credits on their own albums.

K-pop as we know it is really a culture of youth, a culture of newness. Suk-Young Kim, professor at the University of California, Los Angeles

Things caught up for BTS at home in South Korea in 2015 thanks to the The Most Beautiful Moment in Life EP trilogy. The band’s success, locally and internationally, was cemented the following year, when Wings became the highest-charting K-pop album ever on the Billboard 200. “My mom, and every friend and family [member], called me like, ‘What the ??’” Rap Monster recalls. “That’s when I went ‘OK, this is big.’”

The trio of Most Beautiful Moment albums marked a new era for BTS’ sound, as the group began to feature melodic vocals, rap, deep-bass and electronic elements. Music videos like “I Need U” and “Run” featured complex, philosophical story lines and were paired with dramatic choreography for onstage performances.

BTS’ genre blending is typical of K-pop, which isn’t just pop music from South Korea, explains Dorof. “Korean pop, K-pop, is a kind of systematized approach that is kind of a perversion of the Japanese J-pop model, which itself is a perversion of the Western boy band, girl group pop model.” Music videos and starry dance performances abound alongside the music itself. Most K-pop “idols” are in their teens or early 20s (Jin, at 24, is the oldest BTS member); they must sing, dance, act, model, emcee and/or, increasingly, produce. It is multimedia by nature, explains Kim, and a product of the internet age.

BTS points to Western musicians as inspiration — Drake (Rap Monster), Justin Bieber (Jungkook) and John Legend (V). But they’re Korean to the core, raised more by their record label BigHit Entertainment than American pop charts. Each of the members brings his own influence: Before BTS, Suga, Rap Monster and J-Hope were part of the Korean underground music and dance scenes. Jungkook often uploads covers of international hit songs to YouTube. Jimin studied modern dance, and V recently began acting.

But one thing all the members share? Growing up in the aftermath of the 1997 Asian financial crisis. After the International Monetary Fund bailed South Korea out of debt, the country’s economy and workforce shifted models to value young, more disposable workers over the older, less cost-efficient generation. “Somehow K-pop rose within that movement,” said Kim. “K-pop as we know it is really a culture of youth, a culture of newness.”

Yet BTS’ version of youth is rebellious: They present as artists who eschewed the competitive scholastic rat race. Beginning with their debut track “No More Dream,” the group urged listeners to “Rebel against the hellish society” where “dreams are a special pardon.” Later, in “Silver Spoon,” they bemoaned, “We’re cursed at, this generation.”

Rap Monster says the group pulls from fan letters to understand where young people’s angsts lie. But they’ve sometimes gone astray of their loyal fan base, which calls itself ARMY. Last year, weeks after a prominent rape and murder of a young woman in a Seoul subway station led to national conversation about gender violence, BigHit issued an apology on behalf of BTS for past misogynistic statements by the members and some of their songs, including calling women “gifts” for men in the 2014 single “War of Hormone” — “My eyes keep turning to the girls/ Girls are like an equation, us guys just do them.”

Although the band isn’t yet breaking up, some of them are already going solo. Suga’s Agust D mixtape revealed his struggles with anxiety and depression, and Rap Monster collaborated with American rapper Wale on “Change,” a track discussing police brutality in America alongside South Korea’s rigid hierarchies, competition and high suicide rate.

During the first of their many sold-out shows on American soil, BTS’ hectic world tour schedule caught up to the septet. They were visibly tired onstage. But as the March night came to a close, ARMY lit up the stadium in an array of colorful lights to show their support. “ARMY is my rainbow,” Jin declared, blowing a kiss at the crowd. Suga and Jungkook laughed at the cheese, but ARMY just roared back in adoration.