The singing voice is a double-reed, twin resonator acoustic musical instrument. The resonance system comprises one fixed, switchable resonator and one variable resonator, along with an additional optional post-resonator.
The two main resonators are the pharynx, (the lower or first resonator) and the nasal cavity (The upper, or 'number two' resonator). The two cavities are connected by means of a narrow port located to the rear of the palate. This port may be closed by the action of the soft palate, thereby disabling the upper resonator.
The third resonator is created as needed by the action of the tongue, and may be placed either towards the teeth, creating a cavity bounded by teeth, hard palate and tongue, or under the arch of the hard palate, creating a cavity bounded by the hard palate and the tongue.
One of the chief objectives in singing voice training is to train the singer to allow both resonators to operate at all times in an unrestricted and un-distorted manner. Full-time dual resonance is the primary hallmark of the 'singing voice'. In speech, the use of upper and lower resonators is varied by many factors such as the language spoken, accent or dialect, loudness and emotional state of the speaker. The training singer must therefore learn to allow the vocal tract to operate in a different way. This is made difficult because speech habits are very firmly ingrained, and because allowing the vocal tract to enter a different way of working feels very strange to the singer.
The singer's task is made less difficult by the fact that the process of singing is one that is natural to the body. There is an entire hard-wired system in the body that deals with pitch, timbre, air-pressure and loudness. However this singing system, or 'singing reflex', is turned off during speech. Our chief concern therefore as learning singers is to remove the blockages which prevent the singing reflex from operating. These blockages are throat tension, ear/voice disconnection and attempted direct control. The underlying causes of these blockages are speech habits, inappropriate emotional affect, incorrect mental imaging, poor body use and listening faults.
The Singing Reflex is a group of responses in the body that cause a particular type of sound to be made. Among these automatic responses are:
(Note the absence of the mouth from the above list... the mouth is the 'voluntary' part of the singing voice, where we can do artistic things.)
To get this all to happen, we need to do the following:
In conclusion of this summary, here are some basic principles of voice, re-stated. You may not understand them all right away, but they are the core and centre of your development work as a singer, and learning exactly what they mean and feel and sound like) is the path to enormous understanding and vocal ability.
Inappropriate emotional affect: e.g. actress internalising anger, rock and roller wanting to act agressive.