Kim Jisook’s Vocal Analysis

Vocal Range

E3 ~ F5 (2 octaves and 1 semitone)

Supported Range

Bb3/B3 ~ A4/Bb4

Voice Type



  • Second strongest vocalist in Rainbow
  • Able to produce tone with some breath support
  • Lower range retains a forward full sound down to Bb3/B3
  • Mixed voice shows support up to A4/Bb4, with inconsistencies
  • Doesn’t force her lower notes out with a low larynx
  • Intonation is mostly accurate within her supported range
  • Tone can be present in her lower range below Bb3

Points for Improvement

  • Even within her supported range there can be inconsistencies
  • When singing louder, tends to rely less on breath support
  • Sings with a shrill tone above Bb4, generally becomes tight
  • Lower range below Bb3 is often airy and doesn’t project well
  • Falsetto transitions are often sloppy
  • Unable to produce accurate or smooth vocal runs
  • Falsetto is very airy and somewhat pitchy
  • Tends to be nasal throughout her range
  • Voice tends to lack in dynamics due to lack of development


  • Lower register: Generally unable to project very well in her lower range. Tone is generally present even below her supported range, however support is only kept down to Bb3/B3.
  • Mixed register: Her mixed voice is generally quite thin and squeezed above B4. Below B4 she’s able to show some support with inconsistencies due to unevenness of mix and lack of breath support.
  • Upper register: Her weakest register by far, she’s unable to transition into it without some sort of difficulty and when done so well, she still sounds mostly uncomfortable, airy and somewhat unstable.


Jisook is a vocalist who doesn’t often sing R&B songs. Her style is generally very bubblegum-pop oriented, with songs that don’t often highlight complicated riffs or melismatic ideas. Thus this area of her singing is generally quite underdeveloped and unexplored. When faced with songs that require more vocal agility, she often shows difficulty in singing with accuracy in pitch. She mostly tends to sing runs by sliding through notes without even truly attempting to sing each note one by one and shows that she did not take the time to breakdown every single riff in a song, and instead chose to guess the notes when performing. This shows especially when she sings covers that usually are done by artists who sing more melisma-heavy songs, where she becomes pitchy and her runs are often sloppy, such as in “Stickwitu“, “길에서“, “사랑했잖아“, “Listen” and “보고싶다는그말도“.

Overall analysis

Jisook debuted in 2009 as Rainbow’s lead vocalist. For the past few years, there’s been little to no exposure for Rainbow’s vocal ability and thus none of the members, even their main vocalist Hyunyoung, have been able to participate in shows that highlight vocal ability such as “King of Mask Singer” or “Immortal Song 2”. However, they’ve had the chance to come on many other shows covering artists songs such as “Yesterday”, “끝까지 간다” and “Perfect Singer”, thus being able to showcase their vocal ability to an extent. Jisook’s voice has been showcased as being soft, girly and bright with a light weight and a higher placed range, falling into the soprano fach.

Her lower range is adequate in tone development but still tends to be very inconsistent in support. She tends to be quite capable of producing supported notes in her chest voice down to Bb3/B3, where she’s comfortable and her tone remains fuller and more present, such as in “If I Ain’t Got You” and “사랑했잖아“. However anywhere below Bb3, she tends to become airier and unable to project her voice with as much connection. There have been cases where notes below Bb3 retained tone and she was able to project without pushing her larynx down, such as in “이젠 그랬으면 좋겠네” but even in those cases, support was not fully present and her placement wasn’t forward enough to allow her to fully project down below Bb3. For the most part, her chest voice below Bb3 becomes airy and the tone becomes less and less clear as she descends in tone, such as the A3 in “Black Swan“, G3 in “Tell Me Tell Me“, F#3 in “인연“, F3 in “기억 만이라도” and E3 in “Listen“. This shows a lack of development of her thyroarytenoid muscles, mostly responsible for the production of the chest voice and one’s lower range.

Her mixed voice is one that’s remained inconsistent throughout her career but has shown improvement in her overall approach and support over the years. When singing with a lighter approach, Jisook’s has shown stability of air flow within her supported range and the ability to sing with a relaxed tone, such as the Bb4’s in “보고싶다는그말도” and “기억만이라도“. Compared to earlier in her career, this showed an improved control of her diaphragmatic breathing. However, whenever trying to produce more power and volume in her voice, she tends to become shrill and shouty even as low as A4 and Bb4, such as in “8282” and “사랑했잖아“. This is due to the unevenness of chest and head voice in her mix, which causes her to push her sound out with her throat and chest when trying to create more volume in her mix. However anywhere above Bb4, her approach tends to be either a whiny and tight sound in quality, or a shouted pushed out attempt at being loud. Usually caused by the tension she’s unable to remove from below her supported range and her larynx raising as she gets higher, causing her throat to close around her larynx and her sound to be small and thinned out. This can be heard in the B4’s in “If I Ain’t Got You“, “사랑밖에 난 몰라” and “이젠 그랬으면 좋겠네“, C5’s in “White“, C#5’s in “인연” and “Stickwitu“, Eb5’s in “Hoi Hoi” and “천국“, and E5 in “To Me“.

Her falsetto is by far the least developed part of her voice. Generally Jisook avoids singing songs which require her to venture into her upper register, but when she does there’s a clear lack of tone and projection as she ascends in range. Even though her transitions into falsetto are mostly pitch accurate, she often loses a good portion of her volume output when singing in falsetto, such as in “If I Ain’t Got You” and”사랑밖에 난 몰라“. As a soprano, she has a lot of potential to truly develop a much more extensive head voice but since she limits herself to singing with a disconnected vocal cord approach in her upper register, all she’s able to produce is a shaky and airy falsetto, not allowing her to truly explore the extent of her full range. This can be heard in the Eb5’s in “Mach“, the E5 in “All For You” and the F5 in “Candy Girls“.

In terms of overall technique, Jisook’s voice is not nearly as developed as it could potentially be if she were to explore further approaches into her singing. She has yet to develop better breath support and consequently, she often strains in a relatively low range for a soprano. Her placement is generally in her nose throughout her range and she’s unable to produce full tone or resonance at all. She does however have sufficient control of her voice to be able to sing through songs without necessarily going off pitch and she has the natural ear to know when to sing louder or softer. All she lacks is the proper technique to do these things in a healthy manner where she can truly control her voice through those dynamics changes and transitions throughout her range.

As an idol group, Rainbow’s music is not often very vocally challenging and when it is, Jisook is not the first choice to sing the higher parts in songs. Since none of the members have participated in shows that expose them vocally, none of them have truly been able to be challenged enough so that they are motivated to improve. For now, the way Jisook sings is completely fine for the time of music she releases, however for the future if she chooses to remain an artist and continue singing on as a soloist, major work would need to be done in order to further develop her voice. First and foremost, breathing technique and placement should be addressed, as well as developing her chest voice and head voice in order to create a more developed instrument overall.


As a singer and musician, Jisook generally sticks to simple covers and doesn’t often try to sing with too much embellishment. She sings mostly exactly what the original melody of a song has and will only struggle if she has to sing complex vocal lines or vocal runs in general. She doesn’t try to add her own musical ideas, instead being safe and choosing to just sing the song as the original artist would have sung it. In some cases, she has shown that she’s able to harmonize with others but lacks the full ability to blend her voice well, such as in “All For You” and “Stickwitu“.

Label (Type of Vocalist)

C Vocalists: Commercial Vocalists

Vocal Range Video(s)

Video by: kpoparina

Best Vocal Performance(s)

Analyzed by Ahmin (Kitsunemale)


17 thoughts on “Kim Jisook’s Vocal Analysis

  1. Judging by her supported range, i thought that she might be average lol too bad she doesn’t have much chance to showcase her singing :/


  2. It’s kind of nice that her best performances are more recent ones. I guess it’s a good sign that she can improve over time. I think if she keeps on singing and practicing well, she can improve even more (meaning I don’t think she’s quite hit a wall like it seems some vocalists have).

    Liked by 1 person

  3. I made a vocal range summary for her. It only shows her highest notes in falsetto and mixed voice and her lowest notes. i didn’t want to do a whole vocal range video because I have a lot of singers to catch up on. Here you go!

    Liked by 1 person

  4. Ahw, I thought she would be ranked at least as average, I guess I was wrong :-/ I hope she improves in the future (If Rainbow still exists by then </3)

    I also thought she was a main vocalist (alongside Hyunyoung), while Jaekyung was the only lead vocalist in the group (that's why she gets so many lines lmao).

    Anyway, thanks for this vocal analysis ❤ Fighting!

    Liked by 1 person

  5. May I ask how you choose to analyse a member of a group?
    Jisook for example is listed as a main vocal on some sites, alongside Hyunyoung.
    But she is the second strongest. So how was it decided that she would get a vocal analysis as well?
    Just curious. ^^


    1. We usually analyze half of the vocalists within a group. SNSD has 8 members as vocalists, 1 main and 3 leads so we analyze 4/8 vocalists of the current SNSD. Now we usually take into consideration also if there are rappers, like U-Kiss is a group with 7 members but 2 rappers, so we analyze half of 5 vocalists and that would be their main vocalist Soohyun and lead vocalist Kevin. Sometimes we analyze more if their level of technique is high enough and sometimes we analyze less if their level of technique is not high enough. Apink we only analyzed Eunji because she is a strong vocalist but every single other member of Apink is weak. Anyway we USUALLY analyze half of the vocalists, the strongest vocalists who’d be lead and mains of their groups.


  6. Hey i have a question! Do you watch produce 101? I want to ask your opinion on Yeunjung & Sejeong’s vocal. Can you watch video of their singing on youtube and tell which one do you think is better vocally? Thanks!


    1. Please, I ask that in the future when you ask questions like this provide us with links. We don’t have the time to look for videos to answer questions like this, I apologize. However I’ve heard enough of them and they’re not bad, but they’re not exceptional vocalists. Both of them have issues with supporting above C5 and don’t produce resonance..none of the girls of Produce 101 could support above C5.


  7. I always thought she was better than hyunyoung… But after reading both of their analysis I now know why 🙂

    I know what I’m about to mention is not related to this artist but I would like your opinion on Little Mix.
    I would like to know your thoughts on the group as a whole. What I mean is are they generally a strong vocal group. Also who would you say is the strongest vocalist out of the four of them?

    Here are some links:

    Wings (acoustic) –

    Acoustic version of how Ya doin –

    Move –

    Black magic (acoustic) –

    The links are listed from oldest to most recent.

    Thanks!!! 😀


    1. Yeah, they aren’t Kpop so we won’t be taking the time to actually analyze all of them. However, Perrie is the strongest in the group from what I previously knew


    1. It’s her inconsistency and her shallow support. She doesn’t seem to be singing any differently from usual. Throatiness on the phrased and sustained B4’s, shallow throaty approach throughout with some support.


  8. Don’t you hear improvements from her here? I think she kind sounds more supported but I’m not sure if I’m mistaken it with chestiness + throatiness, but she sounds more full in tone and it seems like her support is better established but I’m not sure.

    you can skip from 1:15 till 2:51 and after 3:36 till the end.
    Thank you.


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