Breath support is one of the first concepts aspiring singers encounter when reading or hearing about vocal technique. Unfortunately, it is mired in myth, ill-defined concepts, and muddled thinking. Accordingly, the purpose of this post is to provide a clearer way of thinking about breath support.
To begin, we will consider the power-source-filter model of singing, which was gradually developed by various vocal scientists but which is, in the world of singing pedagogy, primarily associated with Estill Voice Training. The power-source-filter model consists of the following three parts:
The respiratory system, which acts as the power generator
The vocal folds, which act as the sound source
The vocal tract, which acts as the filter
These three parts work together to produce the final sound. The lungs are compressed by the relaxation of inspiratory muscles (eg. the diaphragm) and the activation of accessory expiratory muscles (predominantly abdominal muscles). In conjunction with the vocal folds acting as a valve, this generates pressure that drives the vibration of the vocal folds. Finally, the sound is given shape by the filter as certain frequency areas are dampened and others conserved. There is a substantial interplay between the filter and sound source, but as our present focus is on the power subsystem, we will set aside the discussion of such interactions and return to them in future posts.
The first realization key to understanding support is that the lungs are, in effect, a valved container that can be pressurized, and as with any such container, the pressure can only go as high as the valve will contain. Beyond that, the valve is burst open. Moreover, a certain amount of pressure is needed simply to set the vocal folds in motion, and beneath that, no phonation will occur. Thus the vocal fold closure — ie. the tightness of the valve — narrowly constrains the amount of pressure or support energy.
What this means in practical terms is that the respiratory system and the vocal folds always work in unison. They can of course work badly in unison, but they do not work independently: a substantial adjustment in one subsystem necessarily coincides with a substantial adjustment in the other — at least if the vocal folds remain in vibration. For this reason, a dichotomy arises when singing: we can either make changes in the support and let the larynx adjust to it, or we can make changes in the larynx and let the support adjust to it. These each have their uses, which will be explored later. For now, we will simply refer to them as "breath leads tone" and "tone leads breath" respectively.
Defining support power
The second key realization is that while support can increase or decrease in intensity, the relationship between pressure and airflow is determined by the larynx (in conjunction with the vocal tract, for reasons that will be explored in future posts) and not the respiratory system. In a technical formulation, we might say that the power subsystem has a strictly one-dimensional output, ie. support power can increase or decrease, but the respiratory system cannot by itself control the degree to which that manifests as increased pressure versus increased airflow.
Let us briefly stop to consider some terminology. We have so far been referring to a power generator, and to increases and decreases in support power. Power is of course a term used in physics, measured by the unit watt. It happens to be the case that the units for airflow and pressure combine to watt. In fact, support power — also known as pulmonary power — may be technically defined as the product of lung pressure and airflow. This product is what we are referring to when speaking of the power generator and support power.
So breath support allows us to increase or decrease support power and that is all. It is in a sense charmingly simple and straightforward: just one variable, and it happens to be tightly constrained by the other two subsystems. I am afraid those who have been sold on breath support as some kind of vocal panacea have been deceived. Furthermore, it is largely the expiratory muscles that are responsible for support. Whenever you find yourself working intensely in the core musculature, using great levels of support, you are generating high levels of pressure. The idea that strong support consists of using inspiratory muscles to reduce pressure is simply incorrect, as it is the vocal folds themselves and not the inspiratory muscles that hold back the air.
Remembering our dichotomy, the "tone leads breath" approach promptly recommends itself: there are many adjustments we can make in the larynx; its output is far from one-dimensional. There is no way of qualitatively differentiating these in the respiratory system; therefore, we can get a more delicate control using "tone leads breath" than using "breath leads tone".
While this is generally true, and I do recommend this as the general strategy for singing, the opposite approach has certain situational uses which should not be neglected. In particular, there is a tendency for the false vocal folds — responsible for some types of distortion — to approximate when very great pulmonary power is employed. This mechanism is known as the Valsalva manoeuvre and it is useful in rock singing for obvious reasons. However, since approximation of the false folds when done to a lesser extent, or in combination with a different vocal tract shape, can add firmness to the tone without engaging distortion, it also has uses in styles that do not call for effects. Finally, it has some uses in stabilizing the laryngeal mechanism and preventing voice cracks, especially in the upper range.
The proper study of support
If support is one-dimensional and tends to simply adjust to the changes in the larynx and vocal tract, it may seem like there is no purpose in paying attention to it at all. This is not quite the case, as we are about to see.
Support is essentially about respiration, so it relates to a dynamic view of posture as opposed to the static view more frequently encountered. Since the ribcage is connected to the thoracic spine, which in turn is connected to the cervical spine that supports the neck and head, the postural movements we undergo when breathing will lead to changes in the vocal tract throughout a phrase. This can have profound effects on registration, but since this is something of an advanced topic, and since experienced singers typically navigate these changes fluently without ever having paid conscious attention to the subject, we shall not explore this aspect of vocal technique in this post.
The second and more important aspect of support is somatopsychic, that is, it relates to the effects of bodily movements on the mental state of the singer. The respiratory cycle becomes exaggerated in singing — the inspiration is sped up, the expiration is sustained and typically altered in intensity in either direction, etc. — and this tends to imbue the respiratory cycle with a certain style. It may be bouncy, punchy, flowing, dramatic, explosive, etc. One singer may have a relaxed posture with a slight slouch, low relaxed breathing that is mostly tidal, etc. By contrast, another singer may be doing thoracic breathing in a posture so upright and with breaths so full that the sternum elevates and creates the appearance of pride or even heroism.
The point is not that the former kind of singer is lazy and should adopt the manner of breathing used by the latter. The point is rather that these singers are likely to be singing very different songs that express different emotional states. Emotional states are however embodied in a person's posture as readily as they might be contained in a song, and just as it would be difficult to sing a mellow ballad while headbanging, so too is it hard to sing a pop song while breathing like an opera singer or vice versa.
My recommendation is this: when singing a dramatic song, use dramatic breathing. When singing a bouncy song, use bouncy breathing. When singing a relaxed song, use relaxed breathing. Always your mind should be of one intent — unless you are trying to depict a character caught up in a tense struggle against himself or some such.
It has been my experience so far that most support-related problems consist of a conflict between the musical intent and the affect embodied in the singer's movements. For example, a singer trying to sing a high note in a bold and open manner may fail because of a timidity that leads him to draw backwards and drop his gaze. In such a case, it is likely he can be helped by practising a more suitable movement without singing, then reintroducing the phrase in an easier key, and taking care to keep the movement extraverted as he approaches the original key.
Singing is essentially a particular type of acting, and nowhere does this come through more than in the study of support technique.
Summary
The respiratory system and the larynx always work in unison and cannot diverge very far without causing the vocal folds to cease vibrating.
Support power can increase or decrease, but cannot be qualitatively differentiated except via the larynx and vocal tract.
Breath support is no panacea.
Intense exertion in the core musculature — ie. "strong support" — means you are generating high pressure.
For most singing purposes, support should "passively" adjust to changes in the larynx.
Active support adjustments are useful for distortion effects, for a certain firmness of timbre, and for stabilizing and/or intensifying the upper range.
Postural movements associated with respiration can affect the vocal tract shape throughout a phrase.
When singing relaxed songs, use relaxed breathing, whereas when singing dramatic songs, use dramatic breathing, etc.