Jung Kook from BTS has put out a collaboration with Charlie Puth. Released June 24, his versatility is right at home in “Left and Right.” The song introduces a gimmick where the audio pans left and right, sending the sound here and there, and Jung Kook picks up the vibe Charlie lays down in the first verse to expand on it further with added dynamism. Jung Kook has a slightly brighter vocal tone than his partner, and while Charlie uses Post Malone-esque autotune vibrato, the BTS member employs vocal fry (where his voice sounds gravelly) during his verse to add a stylish, playful twist. The song clocks in at under three minutes, but he leaves an indelible mark. At just 24 years old, and in just 10 years’ time, Jung Kook has already established a singing style all his own.

Looking back on 2013, when BTS debuted, Jung Kook was a fairly rare main vocalist for an idol group at the time. Throughout the 2000s, the main vocalist position in second-generation Korean idol groups was generally occupied by “power” vocalists who could hit all the high notes with ease. The idol scene was already dominated by hip hop/R&B and EDM-influenced pop by that point, yet there remained a common perception that the only truly skilled singers were those who could sing in a high register. So if you were going to be seen as a skilled idol, you had to be able to really belt it out. But as artists like BIGBANG’s TAEYANG and 2PM lead vocalist Jay Park began to emerge in the late 2000s with vocals more closely aligned with the American R&B scene of the time, a new preference was gaining a foothold. The era also gave birth to many underground R&B singers. The popularity of hip hop grew in Korea as we entered the 2010s and accelerated quickly. Many alternative R&B vocalists have been rediscovered or found popularity for the first time after being featured on songs by popular rappers and producers. Starting with younger listeners, there was a growing perception that vocalists who knew how to convey their own unique sound rhythmically rather than through loud and excessive emotions, such as Junggigo, Zion.T and Crush, were new, cool and hip. Then, when BTS debuted as a hip hop idol group in 2013, they chose 15-year-old Jung Kook, with his innate sense of rhythm and airy voice, to be their main vocalist, rather than someone who belts out their songs. The nature of his vocals made BTS’s music feel fresher and chiller, and separated it from then typical K-pop pathos—its so-called ppongkki. The direction the group and Big Hit were taking at the time can be heard in tracks such as “Like” off their debut EP.

Much can be said about Jung Kook’s vocals, but his sense of rhythm in particular is unparalleled. His understanding of a song’s rhythm seems to be baked into his body, seen both in the way he dances and in the way he’s able to express himself through his vocals. The intro to “Airplane pt.2” off the album LOVE YOURSELF: Tear is a prime example: The characteristic bang of the claves, borrowed from salsa music, is played in 4/4 time but slightly off the beat, shaping the deeply emotional but undeniably danceable atmosphere of the song. In the first verse, Jung Kook lets out a breath after the words “strange kid” directly on the stressed third beat of the bar of the clave rhythm. It would be easy enough for a performer to pass this beat over on a 4/4 song that typically follows a strong-weak-medium-weak pattern, but here Jung Kook hops into the underlying rhythm of the clave instead. As he clearly has a good handle of his singing, listeners who aren’t at all familiar with a clave rhythm can easily follow his vocals to immerse themselves in the salsa atmosphere of the song.

His sense of pitch is excellent as well. When he sings a cappella, Jung Kook can almost always find the correct notes right away. It’s generally believed that only one person in a thousand possesses perfect pitch. There are also people who aren’t born with true perfect pitch but can memorize the pitch of a particular song after consistent practice. In Jung Kook’s case, it doesn’t seem to matter whether he falls into the former or latter camp; neither would come across as a surprise to anyone, given the amount of practice he puts in and raw talent he possesses. His sense of pitch seems to have an effect on his songwriting as well. He is said to have written the music for his song “Still With You” before any beat was decided on by simply setting a metronome and singing the melody overtop. However, this song is written in a jazz scale and has a lot of dramatic interval leaps, making it hard to sing even with the accompanying instruments. This is likely the result of his ability to accurately conjure up and single out notes in his mind and sing them correctly, as though pressing down on a key on the piano. Considering his equally impressive ability to repeat vocals he’s heard before, he seems to have not only a keen sense of pitch, but one of overall hearing as well. He told Weverse Magazine in an interview from last July that he is able to recognize that ability in himself, acknowledging he “can hear [the characteristics in their voices]” but that he “shouldn’t [just imitate] it that way.” This skill of his ultimately becomes one tool of study with which he is able to create a style of his own.

His vocal technique, too, is tops, but I think it would be better to analyze some of the styles he has sung in and discuss some of the different techniques he uses as we go along. In an interview from early 2021 titled “Jung Kook’s BE-hind ‘Full’ Story,” j-hope said the most notable strength of Jung Kook’s vocals is that they’re “relaxing.” Many things likely contribute this, such as his tone, vocal technique, choice of songs and his interpretation of them (which I will discuss later), but, from a technical viewpoint, he likely finds a balance in the way he uses his vocals cords to keep them open. Not only does this keep his vocal cords in good shape, but it makes for easy listening regardless of what he’s singing because he doesn’t have to push them too hard to make sounds. (Of course, there’s something to be said for the artistic choice to create an air of desperation by restricting the vocal cords or singing in a chest voice instead. Neither approach is wrong, just a difference in expressive style.) Jung Kook’s vocals always come with a dose of breezy breathiness, playing a key role in his smooth transitions between chest and head voices. This also makes the listener feel closer emotionally with the singer, since his vocals give the impression of someone whispering in your ear. Even his pronunciation seems to have benefitted from nearly endless observation and practice. Korean vocal coaches are quickest to emphasize that Jung Kook’s vocals are more closely aligned with American pop singers than Korean singers traditionally have been. Considering how the very way of making Korean and English sounds is fundamentally different, Jung Kook was likely doing the same as other alternative R&B singers in Korea in the 2010s, constantly listening to English songs and adapting that style to sound more suitable for the Korean language. The defining characteristic of his vocals is that they sound so relaxing to listeners, and this is thanks to his acute sense of rhythm and pitch as well as his practice- and study-driven technique, all of which leads to consistently impressive vocal performances. In the nine years since his debut, he has trained himself in these features through immeasurable practice and countless performances, and the growth he has achieved is remarkable.

All of the talents covered so far really bolster one thing: musicality. With the popularity of dance competition TV shows, musicality is a very familiar term. It is, in short, a talent for expressing music. In the case of dancing, it’s commonly said that it isn’t enough to simply show off your skill set; you have to be able to communicate the music as though you truly feel and melt into it. In dancing, someone might be said to exude musicality when their body and the music appear to move together as one. The same goes for singing. Everyone gets the exact same sheet music, but it’s up to the performer to determine how best to interpret and express the song for listeners. When j-hope called Jung Kook’s vocals relaxing in the “BE-hind ‘Full’ Story” interview, Jung Kook responded by saying, “If I just cram my color into the song, the song will collapse, won’t it? … But for me, if there’s a song, I think I just paint my feelings onto the song as if I’m coloring.” When you listen to him singing, it really does sound that way. That’s not to say that he takes a passive approach to music, however, but that he delicately varies his emotion according to the direction each song takes without betraying any of the song’s fundamental character.

Let’s take a look at when he sang “If You” on King of Mask Singer. Not only was the original written to be sung by the five members of BIGBANG, but it’s also written in such a way that the first and second verses are separated by a whole octave to give parts of the song marked contrast. Jung Kook rearranged the song to be sung solo and so that the emotional intensity rises with extreme subtlety. Rather than taking a more intense approach to the chorus, he continues his gentle style from the bridge, only adding in a tantalizing touch of vocal fry and more of his breathy technique. It was a perfectly suited interpretation: one that starts in a whisper to pull listeners in and lead them to listen more attentively.

“My Time,” Jung Kook’s solo song off BTS’s album MAP OF THE SOUL: 7, gave a comprehensive look at all the skills he had been refining up to that point. His vocals emphasize the repeated staccato and soft legato of the guitar, fluttering synth and irregular trap beat. He makes it sound so easy. He knows when to run counter to the beat, when to relax or tighten up and when to burst forth, and does it all with perfect artistic timing. It resonates with the title of the song and makes me feel the emotions that much more deeply. Even the way he puts an edge on his vocals as they run against the crunchy guitar is another example of his excellent emotional analysis and expressive ability.

Jung Kook has said that lately he’s more interested in singing in a way that better reflects his speaking voice. The interview he did with Weverse Magazine for the release of Proof gives a better idea of what he means. According to the artist himself, whereas he would focus specifically on making his voice sound good in the past, he has recently taken to practicing with the idea that he can sound good even with his natural voice. This change could even be heard in his vocals on “Stay Alive,” a song SUGA wrote for the webtoon 7FATES: CHAKHO. Jung Kook said he had a hard time recording the vocals because he wasn’t used to the style and had to give it several tries, but once SUGA heard the take Jung Kook offered him, he approved of it on the spot.

It’s a common sight to see in BTS’ documentaries and work logs that others who work with Jung Kook are impressed with him and the work he does while Jung Kook himself says he wants to improve on himself. It’s fascinating to see the artist eager to grow and continually changing even 10 years after his debut. He was already impressive at age 15, but he’s since come so far to reach where he is today that it’s difficult to quantify just how much ground he has covered in that time. BTS was making strides that whole time and Jung Kook, the youngest member, was right there making strides with the rest of them. His name is attached to countless records, including the youngest Asian person to top the Billboard Hot 100, the youngest person to ever receive the Hwagwan (Flower Crown) Order of Cultural Merit and the youngest entertainer to attend the UN General Assembly as part of a special presidential envoy. But he remains ever-dedicated to his bread and butter: singing and making music. Jung Kook’s love of music shows in the way he aspires toward self-improvement. Despite working in the industry from an early age, he shows no signs of tiring of music. As a music fan, as I watch this professional work, I feel an incredible sense of gratitude and awe at the same time.

I’m amazed at how passionate someone can remain after 10 years of work, but at the same time I feel like 24 is the right age for that passion. And even though I can’t predict the future, I somehow get this feeling that he will still be working toward the same things he concerns himself with now even when he’s older. The music will still be there. What’s not to love about an artist whose passion burns so bright?