Messa di voce is an advanced vocal or musical technique. It involves holding a sustained note, and changing it’s volume gradually. In a messa di voce, the singer or musician starts at a quieter volume and slowly increases the volume, sustaining the same note at the same pitch, before reaching a crescendo, and then decreasing the volume again.
One critical point about this term, which is Italian, is that the word messa does not translate to “middle” in English. Words like mezzanine, or in musical parlance, mezzo-soprano, include this meaning. Messa di voce is a different term that might be translated as “marking” or “placing” the voice.
As a musical technique, the messa di voce became common in the baroque era. Some musical experts consider the musical technique as predominantly a part of a type of singing called “Bel Canto.” The technique requires quite a bit of discipline, and is sometimes used in teaching music. Instructors can use the very common musical terms “pianissimo” and “piano,” as well as “forte” and “fortissimo,” to describe the changes involved, and the results that need to be achieved.
In more modern times, the messa di voce is less common. Still, this technique provides an interesting contrast within a musical piece, and is still sometimes used in some dynamic vocal genres. Singers who are learning advanced vocal techniques might consider themselves somewhat advanced if they can master this technique. Many vocal instructors claim that this technique is instrumental in helping singers to figure out how to direct the voice for complex recitals or vocal compositions requiring a more sophisticated control of the diaphragm.
Technically speaking, the messa di voce requires something called sub-glottal aerodynamic pressure, which some people would explain as pressure below the throat, from the diaphragm. That means that this technique can also help singers develop more vocal strength for genres like opera. Modern musician training can include the messa di voce as part of a larger more comprehensive vocal instruction.
Presently, some musicians think of the term as related to software or technology products that alter the human voice in certain ways. For example, a software program could be used to create this kind of alternating crescendo and decresendo in vocals. An artificial messa di voce technique might be a part of a studio software system.