Why 2015 Was A Transformative Year For K-Pop: BTS’ Growth, TWICE’s Debut & More Important Moments

In 2024, the K-pop industry continued to grow and absorb worldwide influences, spinning them into its one-of-a-kind culture. K-pop artists are more globalized and multifaceted than ever, securing opportunities that seemed inconceivable just a decade ago — BLACKPINK's ROSÉ scored a viral hit alongside Bruno Mars with "APT.," SEVENTEEN headlined Glastonbury in England, and TWICE teamed up with GRAMMY-winning rap star Megan Thee Stallion on "Strategy," just to name a few.

Of course, those kinds of accomplishments would've never been possible without the global explosion of K-pop that has occurred in the past several years. And while the genre had seen notable spurts of success prior to the 2020s — from PSY's "Gangnam Style" phenomenon in 2012 to BTS' chart-topping breakthrough in 2018 — it may not be where it is today without the year 2015.

At that point, "Gangnam Style" had helped the industry find new eyes and ears eager to consume its content. In turn, South Korea — confident of its cross-cultural powers — invested even more in global marketing strategies, like connecting with fans over social media.

"2015 was a very interesting year for K-pop," songwriter and producer Andreas Öberg, who has been working with K-pop names such as TWICE, NCT 127 and Red Velvet since 2012, tells GRAMMY.com via email. "At this point, the artists and labels weren't as focused on the U.S. market, and the song releases were not as heavily based on instrumental tracks to be toplined. Many of the songs were rather written from scratch, live in the room with instruments."

During that year, Öberg attended several songwriting camps in Seoul and worked with names like BoA, SHINee, f(x), VIXX, and Oh My Girl. "I think that the [2015] albums from EXO and SHINee will stand the test of time. [Their label] SM Entertainment was pushing the envelope with interesting releases, experimenting with many different sounds and styles but still with a lot of musicality," he adds.

Anchored by '70s and '80s sounds, brass-heavy synths, and moody hip-hop, the K-pop music of 2015 blessed us with countless classics: Wonder Girls' "I Feel You," Red Velvet's "Dumb Dumb Dumb," BTS' "I Need U," and many more. According to Öberg, the vibes of these songs lasted for some time, until the K-pop industry started changing: "The big wave of trap music coming from America started making its way, also the huge worldwide popularity of BTS made the labels aim more towards a Western audience and sound."

Add to that the expansion of social media in dictating musical trends, and K-pop is now arguably more streamlined, and less risk-taking. Though that has helped the genre boom, Öberg insists that the "unpredictable and experimental" music of 2015 is what made that year so special. But even if K-pop never returns to what it was then, it certainly wouldn't be the same without that remarkable era.

Ten years later, GRAMMY.com looks back at the boundless creativity of 2015, the defining K-pop releases and acts of that year, and how all of it still shapes the industry today.

In 2015, the so-called "second generation" of K-pop (there is no precise consensus, but generally, it includes artists who debuted between 2003-2011) was still thriving — even though that meant the beginning of the end for some and a reinvention for others.

Legendary boy group BigBang was nearing a decade of existence, but hadn't released new music since 2012's Alive. As if to compensate, 2015 saw them release eight new singles, all of which hit the Top 3 of Billboard's World Digital Songs chart and South Korea's Circle charts (formerly Gaon), proving that they still had what it takes to be a top group. They incorporated trap beats and country guitars in the suggestive "Bae Bae"; revealed their deepest insecurities in the acoustic "Loser"; went all out in the jarring, unstoppable "Bang Bang Bang"; and plunged right into alt-punk rock in "Sober." These singles would later be compiled into 2016's LP, MADE, and overall represented a magnificent, trend-setting era for the band.

For lauded veterans Girls' Generation, 2015 was a time of reinvention. In late 2014, vocalist Jessica's dismissal from the group was met with controversy, as she stated in a press release that her label, SM Entertainment, told her to leave the group after she started her fashion brand, Blanc & Eclare. With Jessica gone, Girls' Generation reorganized themselves as an eight-piece and released their fifth LP, Lion Heart, in August 2015. Spawning singles "Party," "You Think" and the jazzy title track, the album traversed through peppy pop songs, retro inspirations and bass-heavy hip-hop, hinting that lineup changes may have led to newfound strengths.

The K-pop queens of retro, Wonder Girls, also experienced a rebirth in 2015. Since their 2007 debut, they were pioneers in expanding K-pop internationally, even supporting the Jonas Brothers on a U.S. leg of the trio's 2009 World Tour. After a three-year hiatus that many believed was the end, in June 2015 the group announced the return of member Sunmi (absent since 2010) and released the masterful studio album Reboot. Showcasing the quartet's songwriting and composing talents, the '80s-themed record is a non-skip listen that recreates the mystifying aura of that time. Despite reaching No. 2 on Billboard's World Albums chart and lead single "I Feel You" achieving an "all-kill" (topping all the main Korean charts at the same time), the members decided to part ways in January 2017 and follow solo careers.

Other luminaries that released incredible music in 2015 include IU (Chat-Shire), BoA (Kiss My Lips), 2PM (No.5), Sistar (Shake It), and Miss A (Colors, their final EP).

While veteran acts proved they still had plenty to offer, the rising third generation of K-pop solidified its presence in 2015 with remarkable achievements — and some of the decade's finest music.

Boy group EXO had been a burgeoning name since their 2012 debut with Mama, but 2014 brought challenges when Chinese members Kris and Luhan terminated their contracts with SM Entertainment, citing health issues, differences in treatment, and unfair pay. Regardless, EXO released one of their best efforts yet with 2015's Exodus and its repackaged version, Love Me Right. Effortlessly sleek and absorbing, the album is a display of the group's brilliant voices and gigawatt charisma, mixing funk-pop bliss with swoon-worthy R&B moments.

Before they became a household name, BTS was also just beginning to spread their wings in 2015. Since their 2013 debut with single album 2 Cool 4 Skool, the septet put a heavy focus on rap and lyrics that reflected on South Korea's societal issues. With the release of 2015 EPs The Most Beautiful Moment in Life, Pt. 1 and Pt. 2, BTS ventured beyond their hard-hitting roots, crafting what would become their signature style: meaningful lore, poetic and relatable lyrics about life's struggles, and a blend of soft, sweet vocals with searing rap bars. These two EPs, later compiled into the 2016 album The Most Beautiful Moment in Life: Young Forever, remain quintessential to the group's identity, and the popularity of singles "I Need U" and "Run" spearheaded their exponential growth since then.

On the girl group front, 2014 debutantes Mamamoo found a sleeper hit in the chill R&B of "Um Oh Ah Yeh," the lead single off their third EP, Pink Funky, and solidified their place as vocal powerhouses.

Meanwhile, Red Velvet, another 2014 debut, had a career-defining year in 2015. With the addition of member Yeri that year, they released their first EP, Ice Cream Cake, and their first full-length album, The Red. These projects showcased the quintet's sonic duality — the playful "red" side and the sultry "velvet" side — with impressive skill, placing Red Velvet in an inimitable niche that would define them for the next nine years and counting.

One of 2015's most notable trends was the stark dichotomy between girl groups embracing sexy, self-empowering concepts and those adopting pure, innocent ideals in their music and visuals. Although both concepts existed since the beginnings of K-pop, 2015 saw a marked renaissance of the latter, becoming one of the year's trademarks.

A wave of youthful innocence swept through the industry, with a slew of girls dressed in white and singing with voices as crystalline as snowflakes. Groups like GFRIEND, Lovelyz (who debuted at the tail end of 2014), and Oh My Girl found immense popularity with concepts deemed bright, pure or whimsical — as if in response to the growing "sexy" concepts.

That didn't mean pure concepts were lacking in quality. Oh My Girl's enchanting "Closer" and GFRIEND's cotton candy pop "Me Gustas Tu" remain true classics, anchoring much of their future discography even as they have since explored different styles.

Of course, there were still a number of sexier outputs throughout the year. Groups like Brown Eyed Girls dropped dazzling albums like Basic and its provocative single, "Warm Hole"; EXID turned heads by challenging objectification with the trumpet-heavy "Ah Yeah"; 4Minute's Hyuna proudly declared herself "the female monster" on the group's hit single "Crazy."

But after the boom of cute concepts in 2015, the trend overtook the industry over the next few years. Nearly all girl groups debuting in 2016 or 2017, like I.O.I and Momoland, followed this general aesthetic — at least in their first releases. In the meantime, groups like BLACKPINK and (G)I-dle set forward with an iteration of the sexy concept: the "girl crush," where they present fierce and cool styles, often serving as inspiration for other women.

As Andreas Öberg mentioned, SM Entertainment was at the forefront of innovative music in 2015. Two of its most experimental acts, SHINee and f(x), played central roles in introducing a sonic trend that still runs strong today.

First came SHINee's fourth LP, Odd, and its sparkling single "View." Although K-pop had experimented with house music before — particularly electro, like in 2NE1's 2011 hit "I Am The Best" — "View" is widely considered as the genre's first foray into deep house.

Following this, f(x) took charge with their October studio album, 4 Walls, and its eponymous lead single. While "View" mixed deep house with more bright and carefree vibes, "4 Walls" was moodier and almost cryptic — an initiation ritual to f(x)'s new era as a quartet (member Sulli had left just two months prior).

Both Odd and 4 Walls depicted more mature, sophisticated versions of SHINee and f(x), attesting to their growth and commitment to pushing K-pop's boundaries further. Since then, deep house has become a staple in K-pop discographies, spawning hits from EXO's "Artificial Love" in 2016 to Jeon Somi's "Fast Forward" in 2023.

As groups like EXO and BTS soared to new heights, the rookies of 2015 were trailblazing their paths, each showcasing distinct potential that would shape the future of K-pop.

SEVENTEEN, who in 2024 completed a sold-out stadium tour in the U.S., debuted under Pledis Entertainment as a 13-member, self-producing boy group. With their passion for performance and youthful ambition, they brought a refreshing vibrancy to K-pop with their debut EP, 17 Carat. Throughout the years, the group honed their talents and synchronicity, becoming one of the industry's most revered, accomplished acts.

Another standout debut of 2015 was Starship Entertainment's Monsta X, who quickly carved a niche out of rough EDM and rap with their Trespass EP. Mostly self-produced, the group garnered a steady fan base with their powerful performances, embarked on global tours, and ventured into prolific solo careers. Like SEVENTEEN, Monsta X are still active, with new music anticipated in 2025 as all members complete their military conscriptions.

JYP Entertainment's TWICE was one of the most anticipated debuts of that year. Formed through the survival show "Sixteen," the nine-member group set themselves apart by avoiding the extremes of sexy or pure concepts and instead embracing a bubbly, cheerful sound that became their signature for years. TWICE went on to dominate charts worldwide, embark on massive stadium tours, and, most recently, collaborate with rapper Megan Thee Stallion on 2024's "Strategy." Other notable debuts included Day6, GFRIEND, and iKON, who each brought unique colors to the scene, along with R&B singer Dean and solo ventures by Girls' Generation's Taeyeon and BTS's RM.

2015 was a year that will go down in K-pop history as one of its most prolific and audacious, With many of its main players still dictating trends and inspiring younger generations, K-pop's fruitful 2015 marks a legacy that's still making an impact 10 years on — and will likely continue for years to come.