Sound in the vocal tract is created when air from the lungs is sent through the vocal cords (also called vocal bands) which, when pulled together by certain muscles, vibrate: creating sounds. The normal sounds we make in this manner are usually called vowels and consonants. Sound in the vocal tract can also be created in other ways as well: by tapping on the “Adam’s apple” (larynx or thyroid cartilage) or on the cheeks, “popping a cork” with a finger suddenly removed from the inside of the mouth, whistling, etc.

The sounds which are made by the vocal cords are rich in harmonics. We might say “buzzy” or “annoying.”

The vocal tract changes this basic “rich in harmonics” sound into sets of harmonics based on the Harmonic Series ( a fundamental pitch, a first, second, third, fourth, etc. set of harmonics of the fundamental pitch) These harmonics correspond to octave, fifth, octave, major third, fifth, flat seventh, octave, etc.

Any container contains a certain amount of “whatever” – air, water, oil, gumdrops, etc. The size of the container, its shape, length and width will determine how much air is contained in it. Your vocal tract is a container that can change not only its shape, but its size width and length. To create more confusion, the vocal tract is equipped with “gizmos” like a moveable soft palate, a tongue, lips and finally, not in the vocal tract, but nevertheless, a “gizmo” of change – your jaw. Essentially, your vocal tract is (without thinking about the vocal cords at all) like a drum which can be tuned up or down by two octaves or more!

Singers must learn to tune not only the pitches they sing, but the vocal tract as well, so that both the pitch made and the container are “in harmony” with each other.

Vowels are combinations of a “buzzy” pitch from the vocal cords, and two very strong harmonic overtones. This sometimes creates puzzling contradictions for a singer.

The vocal tract can be tuned differently for specific pitches.

This allows a singer to re-tune pitches of the vocal tract which become physically difficult to sing (especially in the higher ranges).

Vowel resonances are “fixed” in pitch ranges called “formants.” A formant is an area of pitch – not a specific number of cycles per second.

Male and female voices produce the same vowel formants. – the “American” AH vowel produces a pitch in the vocal tract in a normal sized person somewhere between E4 (335.5Hz) and G4(398.8Hz).

Approximately one octave lower, the vowels “EE” and “OO” resonate – setting up a triangle as seen on page 14 with the “AH” at the top and the “EE” and “OO” at the bottom. To prove this (that is that the vocal tract is a pitch making instrument): take a breath; hold it (as though you were going to hold your breath) – open your mouth as though you were going to say “AH” and flick your finger against your Adam’s apple. (If you opened your vocal cords (as though you were going to breathe in) you will get a very muffled “thump” without a strong pitch) If you kept your vocal cords closed you will hear a pitch somewhere near F4 (350Hz or so). If you continue flicking your finger against your Adam’s apple while moving your tongue from “AH” to “EE” (slowly) you will hear the pitch of your vocal tract get lower until it is approximately one octave lower at the vowel “EE.”
If you are going to sing any kind of “legitimate” music (opera, lieder, Musical Theater before “Hair”), learning to tune the vocal tract to the pitch you are singing is of GREAT importance. This is what gives a voice its resonant power – without it the singer will be what voice teachers of old called “singing in the throat” – a complete misnomer, by the way!
Let’s examine this “tapping the throat” process a bit more. This is the practical application for tuning the vocal tract to the pitch you are singing. The jaw stays in the “AH” position, even though you are moving your tongue towards the “EE” vowel or the “OO” vowel. The jaw should remain in the “molars apart” position.
Why?
This keeps the instrument at approximately the same size, diameter and shape. – The moveable factors are the tongue and/or the lips – not the jaw. In this manner the vocal “instrument” doesn’t change from a flute to a piccolo or from a cello to a violin as you change singing pitches. This is very important – especially for American singers who tend to use the jaw and the laryngeal position on every different pitch. Watching yourself as you tap on your Adam’s apple, changing the pitches is an excellent exercise for beginners. Attempt to keep the jaw in a singular position – teeth apart as you articulate from vowel to vowel (and thus, from resonant pitch to resonant pitch)
You are still NOT singing pitches….yet!

Laryngeal stability is the mark of a good singer. Most beginners find that their Adam’s apples (or larynx - pronounced Lar (like Larry)- inks…..not lar – nicks! ) moves upwards with the pitches they sing.
Why?
The brain is making an attempt to “tune” the instrument (the vocal tract) as you sing differing pitches. However, with each move upward, the size of the vocal tract becomes smaller and smaller – the sound becomes “shallower and shallower” as the instrument itself changes size. The flute becomes a piccolo.
There are sets of muscles in the throat which can keep the larynx in a more stable condition: either in an “up” position or a “down” position. Most voice teachers attempt to have students learn the “down” position. This works well for classical music and some theater music. The problem with the lower position, is that singers of pop music – especially R and B singers use not only the lower position, but the upper position as well. Musical theater singers of musicals after “Hair” need to be able to sing both the old fashioned “legit” style and the newer pop style of Musical Theater singing.
The “up” position muscles are basically the swallowing muscles which raise the Adam’s apple into a high position where it meets the hyoid bone (the tongue bone).
When held in this position, the larynx is stabilized against the bone and the pitch making muscles can do their work without being “defeated” by the moving larynx. The sound created is usually very “brassy” and ugly as well as loud. ( Fran Dressher of the TV show “The Nanny” or Jerry Lewis and other comedians use this
sound – it is also very intense.) This is part of the R and B sound – high, screamy and intense…. Not very “pretty” but exciting. Sheep make this sort of sound (baa baa baa)
Try it!
If you look into a mirror while making this sound, you will see that the back of your tongue is in a very elevated position. This is very important to be able to do, as it creates a “squeezing” of the air, creating high, intense harmonics which we need for singing. You can actually “feel” the sound strongly hitting your soft palate or hard palate.
Notice also that your larynx is in a very high position. Sing a few notes or a simple song using this technique. The “old masters” called this the witch voice, and it can be very helpful in certain circumstances.