Girl’s Day’s Vocal Analysis: Sojin

Vocal Range

C#3 ~ A5 (2 Octaves & 4 notes)

Supported Range

A3/Bb3 ~ A4

Voice Type



  • Second strongest vocalist in Girl’s Day
  • Support and pitch improved considerably over the years
  • Able to show good connection in her vocal cords and project down to Bb3
  • Has shown support up to the G4 ~ A4 range
  • Falsetto is normally transitioned into without pitch issues

Points for Improvement

  • Takes too many breaths in between phrases, issues with legato
  • Usually places her voice in her nose
  • No register is considerably well developed
  • Pushes voice out with her throat a lot
  • Notes above A4 are usually strained and throaty
  • Notes below Bb3 usually come out airy
  • Mostly sings with a very airy falsetto
  • Unable to produce resonance
  • Support can be somewhat shallow
  • Runs usually lack rhythmic flow and note separation


  • Lower register: Most of her lower range is muffled and lacks projection. Tends to push out more air through her vocal cords than true tone. Able to produce supported tone down to Bb3.
  • Mixed register: Her mixed voice is extensive in range but lacks support. She usually resorts to pushing her voice out with her throat, letting her larynx raise above A4.
  • Upper register: Falsetto is mostly used. Unable to sing with a head voice. Transitions have improved into falsetto, but the tone in her falsetto is usually very airy and at times pushed out.


Sojin is not a very R&B focused vocalist and lacks the influence of such a genre in her vocal style. Thus, it is understandable that she’d be somewhat less comfortable in a song where she’s to sing with more vocal runs and trills. She doesn’t often sing with vocal runs; but when she does, it is possible to hear a lack of true development in this area of her voice. Most of her runs usually lack correct rhythmic flow and come out with somewhat of a laggy approach, usually by sloppily sliding through notes with a lack of precision in pitch and accuracy, as heard in the runs in “눈물이 안났어“, “Umbrella“, “Slow Motion” and”비처럼 음악처럼“. However, when singing simpler trills and much slower runs, she’s able to sing with more accuracy in pitch, such as in “All Of Me” and “Lonely“.

Overall analysis

Debuting in 2010 with the girl group Girl’s Day, Sojin has come a long way with the group’s fame and her own improvements as an entertainer and vocalist. A group that has made its name for its female empowerment songs, with sexy and cute concepts, Sojin has the most distinct voice in a group of Sopranos due to her more husky and slightly weightier quality. Adding that to her slightly lower range, Sojin would be most likely classified as a lyric mezzo-soprano.

The lower part of Sojin’s range is one that, considering her fach, is quite underdeveloped. Most of the time, Sojin shows issues with keeping true tone consistent throughout the third octave and is only heard truly showing support in her lower range on Bb3 and above, as heard in “비처럼 음악처럼” and “Umbrella“. Below Bb3 she shows inconsistency with keeping her vocal cords together and occasionally supports down to A3, such as in “” and “8282“, but at other times is unable to project properly on Bb3/A3 and pushes her larynx down to overcompensate for her lack of support, such as in “비처럼 음악처럼” and “Nothing Lasts Forever“. Anywhere below A3, however, she is unable to keep her vocal cords together and her tone generally becomes muffled and airy without true connection of her vocal cords, creating more air than tone in her voice, such as the G3’s in “All Of Me“, F#3’s in “”우리 사랑 이대로, F3’s in “반짝반짝” and E3’s in “Someone Like You” and “가로수 그늘 아래서면“.

Her mixed voice is generally weighty, and she has shown very good improvement with the support in her voice for this range. Whereas before, she used to struggle more to keep a well connected legato and really engage her breath support when singing, now she has a more stable and consistent control of her breathing technique. This shows whenever she sings up to A4, where she usually shows more of a relaxed and supported tone with very little to no pushing, such as the G4’s in “All Of Me” and A4’s in “Someone Like You“, “8282” and “기대해“. Above A4, however, is where she struggles the most. Due to the amount of weight she carries up in her mix, up to C5 she generally pushes too much chest voice up which causes her to sound throaty and distorts the quality of her sound, such as the Bb4’s in “비처럼 음악처럼” and “All That Jazz“, B4’s in “경고” and ““, and C5’s in “All For You“. Above C5, her mixed voice becomes even thinner in tone, mostly with a high larynx and a headier mix with less balance and more pushing, such as the C#5’s in “여자대통령” and the Eb5’s in “여자대통령” and “비처럼 음악처럼“.

The airiness present in her tone kind of stays throughout her range and although minimized in her middle voice, is very present in her upper range. The upper part of Sojin’s range is never connected, and she’s unable to produce a true head voice, hence lingering more towards a thinner, airier, and softer falsetto. The gap in sound and volume present in Sojin’s voice from her mix to her falsetto is very evident and shows just how much less tone is produced in her upper range. Her transitions however have shown really good improvement, from the sloppy transitions in “Slow Motion“, to her transitions in “기대해“. This lack of support and cord connection in Sojin’s upper range can be heard in the C#5’s in “Something“, Eb5’s in “Show You” and F#5’s in “한번만 안아줘” and “Darling“.

Despite the lack of control and breathing technique present in Sojin’s singing, she’s not unable to sing with a sensitive ear to dynamics. She’s able to properly use airiness in her style to convey certain messages in her vocal performances but due to the lack of support in her voice, she tends to often rely too much on airiness which limits the amount of things she can do with her voice. Her placement being mostly in her nose also hinders her power and makes her unable to produce resonance with her voice.

As a vocalist, Sojin has only recently shown more confidence in herself and has learned to control her voice much better over the years. With a lower voice than the rest of the members in Girl’s Day, she’s also had to sing in a much more challenging range than the other members by having to compete with the high tessitura in the repertoire performed by Girl’s Day. Despite all of that, she’s been given opportunities to show her improvements in shows like “King Of Mask Singer” and should only see good things happen for her in the future if she keeps improving and working on her breathing technique. Easing up the tension in her throat in her mixed voice and enabling more head voice to blend into her mix should help her keep herself from damaging her voice over time with the strain present in her singing in the higher part of her range.


Sojin has shown very good improvement in her vocal performances over the years in terms of confidence and control of her voice. She’s now more sure of the limits of her voice and is more in-control of her pitch and transitions. As such, good improvement has been heard in how comfortable she is with creating her own interpretation of songs musically and is now able to, at times, venture into more risky things such as adding her own melodic changes to songs, such as in “All Of Me” and”반짝반짝“. This is still something new to her and most of the changes are very small and simple, done very scarcely.

Label (Type of Vocalist)

M Vocalists: Mid-Range Vocalists

Vocal Range Video(s)

Video by: Hawaiipups and kpopvocalists

Best Vocal Performance(s)

Analyzed by Ahmin (Kitsunemale)


55 thoughts on “Girl’s Day’s Vocal Analysis: Sojin

  1. so nice to finally see a mezzo in the pop side of female vocalists. Unfortunately Sojin’s not that good. Hahah. I knew she’d land at themost in this category because she’s obviously not close to Minah’s level and Minah’s not even too remarkable either. Still I love her tone and how her voice sounds mostly. Another great review as always~!

    Liked by 1 person

  2. I’m noticing I always love the vocalists in the group who aren’t Light Lyric Sopranos, hopefully Sojin can continue to up her technique! I don’t know if it’s a coincidence or not but love all the Christmas day posts, it’s like a present from you guys!


  3. I had a feeling that she’s a mezzo. But her lower register should be better for her voice type. Many sopranos have a better or same register than her. Did you know that she was a vocal trainer for the group Ulula Session?


    1. She what? Was everybody a vocal trainer when their companies were struggling? Isn’t Ulala Session kind of old? (As in the members.)


      1. Haha they become vocal trainors when their companies are struggling? Makes sense. Yeah the Ulala Session members are all born in the early 80s except the maknae who is born in 1990. So they are in their mid 30’s except the maknae.


    1. Sojin didn’t cross my mind as a mezzo at all but maybe it’s because Girl’s Day songs are all so high she doesn’t get to showcase it much + the fact that she’s underdeveloped technique-wise (although I thought she was at least average)

      Liked by 1 person

  4. I first began to wonder about Sojin being a mezzo and maybe not a light lyric after hearing her and Minah sing Someone Like You. It really highlighted how different their voices are from each other.
    I really thought that Something should have been saved for Minah’s solo since Sojin didn’t seem comfortable with it (there was no rap part so Yura had to struggle with it and Hyeri had like 2 lines). It seems most of their songs are tailored to Minah’s range and style and the rest of the members just have to struggle along. They used to do a lot of cute concepts (Twinkle Twinkle, Oh My God, Hug Me Once) so I wonder if they did not encourage her lower range because it was not considered cute(I hope not). The only one of their older songs I think she had good lines in was Nothing Lasts Forever. Hopefully she is able to have the confidence to improve in all areas and maybe sing more songs that she feels comfortable with.

    Liked by 1 person

  5. Wow that’s a surprise, she’s a mezzo… at first looking at her supported range i thought she could potentially be better than Minah due to her voice type, guess not…


  6. Oh Lord… did not expect her to be an mezzo ( i guess i still have to learn lol ) . I mean i know you should not depend on supported range when comes to decide which voice type someone belongs too. But i mean a mezzo who has consistency issues with A3…..
    I always thought she sounded more mature then the other members ,but she is way older anyways .


  7. Another question: Do you think Sojin would’ve potentially improved her lower range more at this point had she given more chances to sing songs closer to her tessitura than the chances she has been given now?

    Glad she’s been improving recently because I personally prefer her vocal timbre over Minah’s (who has this whininess with her voice that i don’t really like that much) and hope that improvement continues


  8. I think Sojin and Key ( SHINee ) share the same problems i.e. their songs are high for them. Will it affect their voice? Moreover, could this be a contributing factor for their lack of development in the technical aspect of their singing?? Just curious.


    1. It does, it makes them strain their voices a lot more. It can yes, singing in the wrong range for your voice can slow down development vocally.


  9. If Sojin is listed as just a “lyric mezzo”, does that mean that you don’t know if she’s a light or full or is it because she’s in the middle?


    I’ve been waiting for this for forever
    it’s sad that she’s weak, and that after a lot of improvement since debut :/
    at least she’s trying to improve. I heard this in some interview, don’t remember when tho
    btw are you ever going to do sunmi from the wonder girls? I really liked her solo songs and her voice is pretty 🙂
    thanks so much for this tho, you contribute so much to this blog ❤


    1. Since Wonder Girls is a 1 rapper 3 vocalists group, we aren’t going to focus on Sunmi at the moment but maybe in a distant future. Thank you for the support!


  11. I missed a lot of you guy’s post over the holiday season. Now I have to back read through every post cause you happen to have analysed many of my fave idols while I was busy. hahahaha I think Sojin’s tone is a good support to Minah’s whenever they sing so I always love hearing/seeing them sing together especially that Someone Like You cover they did. Thanks for the great analysis! 😀


    1. I TOTALLY FORGOT TO REPLY TO THIS! Sorry. I didn’t get a chance to listen to this the other day when you asked about it and I totally forgot to unapprove this comment so I could see it later on. This isn’t better than her usual at all, I don’t hear any changes in her approach, the key for the first song is pretty low and it lies pretty comfortably within her range. Her transitions into falsetto have improved a lot since her debut and she did well with that, her pitch was mostly pretty nice. It was really pretty though, bless her heart. Both songs were soft and sung within a narrow range. Good songs for her level.


      1. lol it’s okay. thank you. and sorry for late reply too.
        tbh tho, at her age, i’m just glad she’s still improving, even just a bit, instead of keep regressing and join her fellow 30-something idols at weak section. lol
        she seems quite aware of her strenght and weakness too. she always picks songs within her range so she can sings prettily. lol that’s enough for me.

        Liked by 1 person

  12. Hi! It’s me again >3>

    This isn’t as much a technical question I guess, but I was wondering (out of curiosity and wanting to learn, not out of condescension in case it came across that way! ^^;) how you determine someone’s voice type (soprano, mezzo-soprano, etc.)? I’ve obviously never had any kind of vocal training so my ear has no idea what to look for.

    For example, I always thought that Minzy had a deeper sounding voice than Sojin (though I know Sojin always sings high in Girl’s Day songs), so I was like whoaa Minzy is a soprano and Sojin is Mezzo? I know I was obviously way off and I totally respect and trust you and your extensive knowledge, so I was wondering if you could explain to me the differences between their voices that make them their respective voice types? It would help me understand better how voice types are identified 🙂 Thanks so much! I hope this isn’t too much.


    1. Well the thing is that people get confused with “dark voices” and “light voices.” People often think someone who sounds thick, or heavy, is a lower voice type and someone who sounds like a higher voice but it’s important to hear where their voices switch registers. The most important thing is where the voice starts to naturally modulate from chest voice to mixed voice, or from mix to head voice. Actually Minzy does have a questionable voice type and I have at times wondered if she were a mezzo because of where her weight lies. She seems to be weightier in her mix and mixes a bit earlier than a higher soprano but her lower range is also present. It’s just the overall placement of her voice isn’t low enough, she doesn’t seem to have her passaggi happen low enough to me but I could be wrong. Here’s a video you may not have seen that I made which explains more on how to identify different voice types. Also one about “altos.” Have you seen them? They might help!


      1. Ahh, thank you so much! I watched the videos and subscribed to your channel. It did help me understand better, as did your explanation! I also watched your basics on singing and plan on watching the other vocal tips.

        I am a female and have had virtually no musical training (I briefly learned to play the violin when I was younger, for only a very short few years 10-13 years old maybe, and I wasn’t very good at it so it’s irrelevant haha) but I have always had an interest in singing and really want to learn. I just was too shy and nervous to take lessons (and now that I am older – 19 – have unfortunately multiple professionally diagnosed anxiety disorders and am very introverted, which only adds to this lack of confidence and such T_T) though I wish I had. I’m worried it may be a bit too late to start, or just that it may take a very long time for me to notice a real change in my abilities, seeing as I have none and have to really start from the ground up. I’m even clueless as to how to identify notes and such, but I do really want to learn! I’ve wondered what my voice type is a lot which is probably why I have an interest in that. I thought I always sounded more along the lines of a mezzo – if only because when casually singing along to typical female pop songs, it’s always been difficult for me to sing what sounds like “normal”, not super-high notes without a lot of effort (?) I guess, but now I’m thinking that may or may not be the case and maybe I could just be a really untrained (obviously) soprano.

        In any case, sorry this got long and a bit off-topic I guess. But since I discovered this blog recently I’ve been reading so much of it and it’s really made me want to truly learn to sing once and for all and put that urge (and nervousness) to rest. I’m going to practice the breathing exercises in your video to start and I guess go from there. I really appreciate all the work you’ve put into this and your videos, and I’m going to try and put it to good use 🙂 Without this I’d be even more lost as to where to begin, haha. Sorry for being rambly, I tend to do that when it’s late and I have a lot to say :/

        Liked by 1 person

  13. Do you know of any other mezzo sopranos that you haven’t analysed yet still in groups (excluding rappers). I know Hani is, but are there any others?


  14. Hey Ahmin, i remember that you’ve once said that underdeveloped vocalists are harder to distinguish their vocal type, especially the female ones. So is it possible that Sojin is just a weightier fuller-sounding soprano rather than a mezzo? Or is she definitely a mezzo?


      1. Because this case slightly remind me with the Katy Perry one, where some people assume that she’s a mezzo due to her naturally weightier voice, but I don’t think she’s a mezzo.

        Liked by 1 person

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s