Phonation Modes and Registers
Breathy, flow, pressed; chest, head, mix, falsetto, fry: what's physically different and how to blend them.
Phonation modes describe how firmly the folds close and how much air passes. In breathy phonation they do not meet completely: much air, weak high harmonics, a soft tone. In flow (or 'resonant') phonation they close efficiently with a moderate pressure: the sound is rich, clear and easy, with a clearly longer open phase. In pressed phonation the folds are squeezed hard and held: the closed phase is long, airflow is small, the sound is loud but tight, with strong high harmonics and a weak fundamental relative to its second harmonic. The aim in most styles is flow phonation; breathy and pressed are colours to use deliberately, not defaults.
A register is a pattern of vibration of the folds that is consistent over a range of pitches. In chest (modal) voice the thyroarytenoid is dominant, the folds are thick and vibrate along most of their length. In head voice (or light mechanism) the cricothyroid dominates, the folds are stretched thin and vibrate mainly at their edges. Falsetto is a very light, thin mode with incomplete closure. Vocal fry (creak) is a very short, thick fold with slow, irregular vibration, below the normal range. Mixed voice is not a separate mechanism but a gradual blend of chest and head muscle activity, with the balance changing smoothly as the pitch rises.
The 'break' or 'flip' is what happens when the balance shifts too suddenly. It is an ordinary physiological transition, not a defect, and everyone has one (typically around B3–E4 for men, and C5–F5 in women). Singers manage the transition zone (the passaggio) by lightening the weight as they ascend, narrowing the vowel (modifying 'ah' towards 'uh' or 'oh'), lowering the pressure slightly and keeping the larynx stable. 'Pulling chest' means dragging heavy chest quality upward: it is loud and strained and tends to raise the larynx and press the folds.
Style context: classical technique prizes a smooth, even scale and a seamless passaggio; contemporary commercial music (pop, rock, musical theatre) often uses chest-dominant belting with a narrower epilarynx and a higher but stable larynx, as well as flips and breathy onsets as expressive devices. Voice science does not say one is right; it says each has a safe way and an unsafe way. The safe signs are the same: ease of onset, clear tone, stable larynx and no pain afterwards.