Ingo Titze lists the messa di voce as one of his 5 favorite warm ups for the voice. In his research, he has found the messa di voce does the following:

• Engages the layers of vocal fold tissue gradually in vibration, medial to lateral;
• Helps the singer match tension in muscle to tension in ligament;
• Tests symmetry of crescendo versus decrescendo control under continually decreasing lung volume;
• Makes all intrinsic muscles of the larynx work in coordination with changing lung pressure.

Titze, Ingo R. “The five best vocal warm-up exercises.” Journal of singing 57.3 (2001): 51-52.

Writing in 1917, William Henri Zay, an American by birth who went to London to study with William Shakespeare (not the Bard), wrote a wonderful book tantalizingly named Practical Psychology of Voice and Life. In it, he outlines his view on the messa di voce drawn largely through the sensation of the tone as it crescendos and decrescendos. Readers are encouraged to read Daniel Shigo’s wonderful blog on Zay for more in-depth information on this American voice teacher and pedagogue.

The art of “messa di voce” consists in starting a tone very softly, and gradually making it grow stronger in volume until the maximum power of the voice is reached, then gradually to reduce it until the original soft tone is attained. The way to do this skillfully is principally through the intelligent use of the resonance-cavities. Of course , when the tone is very soft, the vocal bands vibrate only slightly on the very edges. As the tone becomes louder through increased breath-pressure, the vocal bands vibrate in greater amplitude, but this takes place unconsciously, and need not be considered by the singer. What he must consider is the position of the tone at all stages, and what might be called the amplitude or extension of its resonance. The procedure is as follows: Start the tone on the timbre, well forward, using only the forward and upper cavities for resonance. The result will be a soft humming tone which will be floating, but will have intensity and concentration. The breath-pressure is gradually increased, and at the same time the resonance is alļowed to become amplified, it extends itself slowly back through the post-nasal cavity into the upper pharynx and mouth, then into the lower pharynx, and then into the chest, and by this time the whole of the instrument is vibrating in splendid sonority. The return to the soft tone is something like an organist’s successive cutting off his stops and closing his swells. First, the chest resonance is cut off, then that of the lower pharynx, then the upper pharynx and most of the mouth resonance; what is left is the original soft tone with which we started.

A certain amount of emotional energy may be introduced to great advantage . It will give much additional glow when the crescendo is at its height.

The idea expressed by the word “amplitude” may very well be continued here; this time in connection with the spirit put into the performance: its swelling up and subsiding; its manipulation like the flow and ebb of a wave of emotion. This makes the whole operation less mechanical, and gives it the character of a spontaneous act.

Zay, William Henri. Practical psychology of voice and of life. G. Schirmer, 1917.

What I most love about Zay’s remarks are that he ties the description to as close as an account of the kinesthesia behind the act of messa di voce, and describes the mechanical act of the “engagement of the vocal fold tissue gradually in vibration” per Titze, but in a more singer-oriented fashion.

That Zay wants the messa di voce to be well-forward is a direct mirror in our time of Joseph Stemple’s Vocal Function Exercises (see below), which assist in the habilitation of the voice through an extremely forward [i] vowel, sung rather quietly for as long as possible.

Zay’s tying the messa di voce to an emotional swell should not be lost as well – it’s an important reminder that the messa di voce, while the king of all vocal exercises (in my opinion!), should always be founded upon an expressive intent and a build of passionate feeling. It is the voice teachers, not the scientists, that remind of that the SOUNDS we make should always be tied to an emotional reflex and coloration.