Building Strong Voices-Twelve Different Ways, Part 3
Austin, Stephen F., Journal of Singing
prov-e-nance (prov'e-nens) n. Place of origin, source. [LAT. Provenire, to originate.]
8. Jaw Opening.1 I remember visiting a local high school to judge a regional competition for high school singers. I was placed in the choral rehearsal room where on the board was written "Ten Rules for Singing" that students were to observe. The number one rule was that there should always be at least three fingers of space in the front of the mouth. At best, I believe that this is a gross simplification of a rather complex issue.
As with many of the other points that I have made in this article, I believe that correct practice depends upon the goal. The amount of jaw opening that a singer uses has very specific implications for the timbre of the voice. If you observe a range of vocal expression and common practice on this matter across musical genres, you will see somewhat different behaviors. Take Mick Jagger (or your favorite rock star), for instance. When he is singing high and loud, his mouth is famously wide open. There is certainly more than three fingers of space in the front-most of us would be able to stick our whole fist in his gaping maw! His vocal goal often is to sing with a powerful chest-belt throughout his range, but especially all the way to his limit at the top. His mouth opening is a crucial part of achieving that goal-he absolutely would not be able to do what he wants to do with his mouth closed.
Female belters (broadway or pop) follow a similar approach to the full throated high voice. Consider the iconic Barbra Streisand. You can go on YouTube and watch her sing "My Man," for instance. She sings in a chestrelated belt up to E^sub 5^, and when she does, her mouth is wide open (and her head is tilted back). I know there are lots of different ideas about what to call the register up there, but the point is that it is a powerful source function with an open quality that she achieves by dropping her jaw. If she closed her mouth it would not work.
A quite different approach is taken by those who sing in a more intimate vocal style. Observe your favorite country and western or folk singer (mine is Willie Nelson). As a general rule their goal is to present the text in a very available way that closely mimics natural speech. If you pay attention to what they do with their jaw opening, it looks as if they were speaking. It would be absurd for them to use the same exaggerated space that Jagger or Streisand use. It would not achieve their artistic goals.
It gets complicated when we look at common practice among opera singers. First, it differs between men and women, and sometimes among men and women. My usual place to start this discussion is to observe the practice of the great soprano Leontyne Price. In my estimation there has been no finer singer in my lifetime. If you observe carefully, the opening of the mourn is quite variable depending upon where she is in her singing range, the dynamic level, and her artistic goals. You will see that in the low and middle of her singing voice her mouth opening is usually quite moderate. The combination of her open throat (lowered laryngeal posture) and her relatively closed mouth opening gives her what some would call the "middle voice" or "mixed voice." There is a strong acoustic signal originating at the larynx providing a rich harmonic spectrum. The timbre is not identified as the chest voice, however. The closed mouth posture has kept the first vowel formant low in frequency so that particular partials from the source are above it in frequency, and, according to Ingo Titze, this is what accounts for the particular quality of sound associated with that articulatory scheme. This is in part what gives us the acoustic impression of "middle register." There are acoustic rules for why this is the case, and for a more complete discussion of the importance of partial formant interaction and "inertive reactance" in the vocal tract, I refer you to the article that I referenced at the beginning of this section, "Flapping Jaws and Acoustic Laws," which appeared in this column. …