How to Sing Like Sungjong (INFINITE): Vocal Range, Falsetto Mix & the Technique Behind It

Singing like Sungjong from INFINITE isn't about chasing a rare vocal range — it's about mastering two trainable skills: raising falsetto without pushing for volume, and connecting that falsetto to chest voice so smoothly that the seam disappears. Both skills are built through targeted technique work, regardless of where your natural voice currently sits.

Safety note: None of the techniques described here should cause throat soreness, a pressed or strained feeling, or hoarseness lasting beyond 24 hours. Sungjong's high notes are produced through breath support and register blending, not by tightening the throat or forcing air. If a falsetto or mix attempt starts to feel effortful or strained instead of light, reduce intensity and rest. Consult an ENT specialist for hoarseness lasting more than two weeks.

Sungjong's Vocal Profile

Sungjong is a vocalist in INFINITE, the seven-member group that returned as a complete unit with its eighth album, LIKE INFINITE (2025-03-06), and has also performed as part of the INFINITE F sub-unit. There is no publicly verified official vocal range measurement for him — reported figures vary widely by source, so any specific number should be treated with caution. What is consistently documented is a high, delicate register with a bright, transparent tone, and a distinctive ability to move between chest voice and falsetto without an obvious break in the sound.

That last quality is the throughline of his vocal identity:

• Effortless falsetto ascent — reaching into the higher register without a visible strain or a sudden shift in tone quality.
• Falsetto-to-chest mix connection — moving between registers so smoothly that the transition point is difficult to pinpoint by ear.
• Open, unpressed high-register access — sustaining higher notes with space in the tone rather than a squeezed or pushed quality.

This combination is why his parts often stand out even in dense group arrangements — the tone itself, and how cleanly it crosses register boundaries, carries as much identity as the pitch.

Sungjong's Signature Songs — by Vocal Challenge

Approaching his discography by what each song technically demands gives you a natural training order. Transpose any of these to a key that fits your voice.

Start at the top and move down only once each technique feels reliable. A full performance from LIKE INFINITE is the destination, not the starting line — it asks you to sustain the falsetto-mix connection across an entire song, not just a single phrase.

The 3 Techniques Behind Sungjong's Sound

Effortless Falsetto Ascent (Lowering Pressure, Not Pushing)

Sungjong's higher notes sound light rather than strained because the ascent is built on lowering vocal fold pressure and shifting resonance upward, not on pushing more air or volume into the note. Learners who try to reach his higher phrases by singing louder or pushing harder usually end up tightening the throat instead, which produces the opposite of the intended effect. The actual mechanism is closer to release than effort — practicing soft, breath-supported glides into falsetto trains the body to associate height with ease rather than strain. Falsetto-focused exercises like sustained soft onsets and gentle upward sirens build this coordination directly.

Mix Voice Connection (Smoothing the Chest-to-Falsetto Seam)

The signature quality of Sungjong's sound is a falsetto-to-chest mix connection so smooth that the register transition is nearly inaudible. This is achieved by blending vocal fold closure and resonance across the passaggio rather than switching abruptly between two distinct settings. The common mistake is treating chest voice and falsetto as separate boxes and flipping between them, which produces an audible break or a "yodel" effect exactly where the transition should be seamless. Slow, sustained slides across the passaggio — repeated at the exact point where a break tends to appear — gradually smooth this seam. The mix voice practice guide walks through this blending process in more depth.

Open High-Register Access (Space Without Raising the Larynx)

Sungjong sustains higher notes with an open, unpressed quality rather than a tight or squeezed sound, which comes from creating internal space in the vocal tract without lifting the larynx as pitch rises. The common error here is compensating for a higher note by raising the larynx and narrowing the throat, which produces tension and a thinner, more effortful tone. Practicing sustained high notes with a relaxed, gently yawn-like space in the throat trains the body to find room for pitch instead of squeezing for it. The K-pop idol vocal style analysis covers how register access techniques like this function as trainable identity markers across K-pop vocalists more broadly.

How to Train Toward Sungjong's Style

Step 1 — Map your own passaggio before touching his parts

Use gentle sirens or slow slides to locate the zone where your voice naturally wants to shift between chest and head voice or falsetto. This zone is different for every singer, so identifying it first keeps the rest of your training targeted rather than a guessing game.

Step 2 — Practice falsetto ascents without pushing

Sing soft, breath-supported glides upward into falsetto, focusing on releasing effort as the pitch rises rather than adding air or volume. The aim is a light, stable tone at the top — not a louder or more forceful one.

Step 3 — Train the chest-to-mix connection directly

Use slow, sustained slides across your passaggio while listening closely for any audible break or flip in the tone. Wherever the break shows up, slow the slide down even further at that exact spot until the transition smooths out.

Step 4 — Open space in the high register without raising the larynx

Practice sustained high notes while consciously keeping the larynx relaxed and low, using a gentle, yawn-like sense of space in the throat instead of lifting effort into the neck. This builds the open, unforced quality that defines his higher passages.

Step 5 — Run an AI feedback loop on a single phrase

Choose a short phrase — ideally one that crosses your passaggio — record it, and use Bloom Vocal's AI coaching to score your pitch accuracy, breath support, register transitions, rhythm, and expression. Compare your playback for where a break or added tension appears first, then for overall tone smoothness. The AI surfaces specific habits, like a larynx rise right before the transition point, that are difficult to catch by self-listening alone.

Check Your Cover with AI

Ear-based imitation has a ceiling: you can't reliably hear your own register break, rising tension, or resonance shift while you're performing. Record a passage that crosses your passaggio — a verse-to-chorus transition modeled on "The Chaser" or a sustained high phrase from a LIKE INFINITE track — and Bloom Vocal's AI scores your pitch accuracy, breath support, register transitions, rhythm, and expression on a 1–5 rubric, then recommends the specific exercises to address your weakest area first. It turns "that didn't sound as smooth as his" into "your larynx rises right at the passaggio, causing the break — drill mix voice and open resonance exercises."

For more on INFINITE's other vocalists, see how to sing like Myungsoo, Sungkyu, and Woohyun. For a broader framework on how K-pop idol vocal styles map to trainable techniques, see the K-pop idol vocal style analysis.

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References

• Sadolin, C. (2000). Complete Vocal Technique. Shout Publishing. [Register blending mechanics, including chest-to-falsetto mix connection and the resonance strategies behind an open, unpressed high register.]
• Titze, I. R., & Verdolini Abbott, K. (2012). Vocology: The Science and Practice of Voice Habilitation. National Center for Voice and Speech. [Vocal fold pressure regulation and laryngeal posture underlying effortless falsetto production and passaggio transitions.]