Imagine walking into the storage rooms of instruments of a symphony. One room holds percussion, another strings, another brass, etc. Imagine that the symphony gets a shipment of new instruments called vocalists (for the sake of illustration let’s consider they aren’t human beings but musical instruments that need to be stored). If we were to store them with instruments of similar type which room would they go in? Probably not the percussion room (even some might look percussive.) They don’t fit in the string section. They would be closest to either the brass or woodwinds section, right? They make noise, not by plucking or hitting or bowing, they make their sounds with air passing across a point of vibration, like a reed or lips compressed into a mouth piece, and then that vibrating sound amplified and modified as they pass through tubes. The only difference between the wind and choral sections is that the wind instruments bypass the vocal chords that the choral section uses, but they do use their lungs to make their clarinets and oboes make a sound.
The point is this: The human voice is a wind instrument.
The first skill any vocalist or wind instrument player learns is the skill of breathing. The control of air is crucial to singing. Try singing a song without breathing. It can’t be done.
The first thing any singer or oboe player does before making one musical sound is to inhale. They fill their lungs with 4 to 6 liters of air and control the release (exhalation) of that air under pressure to produce sound. Without that air they will not be able to sing. They’ll be out of breath before the first line is sung. Dialog and singing is an act of exhalation. Think of the mouth and lips as the keys and valves on an instrument that shape the sound.
The second thing they need to do is prepare for the musical breaks where they will be able to refill their spent lungs in the middle of the song. When we record vocalists and process their recordings, we often reduce or remove the breath sounds for a cleaner song. But we should not remove breathing in our animation performances. Breathing is one thing that gives a sense of life and believably. A well placed breath can be powerful. It’s sometimes a limitation in audio, but this is sometimes a limitation that we want to see in animation, even though we may not hear it. It is a necessary element in our effort at getting great song-sync into our characters.
Inhale! Inhale! Inhale! How is your character breathing? If they have no flow of air they shouldn’t be making any more sound than a trumpet lying on a table. Good song-sync must not simply consider the mouth makes certain phonemes, good song-sync needs lungs filled with air. Make your characters inhale so that your beautiful mouth animation has the exhale of air to make them appear to sing.