Intonation
Intonation, or "Singing in tune", is a conspicuous necessity, since even children know when a choir is singing off pitch. Unfortunately, fixing pitch problems requires more than simply pointing them out to the choir; a director must identify what’s actually causing the problem in order to fix it. So, what causes pitch problems?
I. Vocal Tension
The voice is great at expressing emotion. When a person feels tense, he will constrict the chest cavity, so that less air is taken in per breath. He will also tense his vocal folds, neck muscles, and shoulders, so that less air is required to produce a tone. The result is bad intonation, reduced vocal flexibility, reduced range, and eventual fatigue. The sound of a tense choir or singer is edgy and feels pushed. When the director hears this happening, first identify why it’s happening:
Is the music intimidating them? Are they frustrated?
Do they need more encouragement? Do they sense that their part is "high"?
Do they associate "loud" with "tense?" Do they associate "emotional" with "tense?"
Are my conducting gestures tense? Is my posture or facial expressions tense?
Next, act appropriately. To improve your own physical presentation, practice in front of a mirror, or if you’re brave enough, videotape a rehearsal. If the choir becomes frustrated with or intimidated by the music, either make the learning process more encouraging or put the piece away for another day. If tension comes with loud or high passages, encourage full lungs, loose lips, dangley jaws, and raised eyebrows, in order to increase reasonance and decrease vocal tension. An ascending passage that becomes flat might be mastered first in a lower key, then transposed up incrementally.
II. Poor Breathing or Posture
When we sing, we balance air pressure against the tension of the vocal folds. The relationship is scientific: Let’s say you’re singing middle C correctly. Now, if you decided to use less air pressure (say you’re running out), but still sing the same note at the same volume, you would compensate by using more vocal fold tension. If you decided to use more air pressure to produce the same note and volume you would decrease vocal fold tension to compensate. Poor breathing forces the singer to use more vocal tension, which will often cause flatness.
III. Poor Vowel Unity
Each vowel has a myriad of regional interpretations. In St. George, harses live in borns. In Virginia, they live in barns, with an elongated a and a barely audible n. On the BBC, the r and the n are dropped, and the vowel is nice and round. In choirs, this kind of vowel variety often causes intonation problems. Some choirs spend far too much time carefully unifying each and every vowel and consonant sound, but the end effect can be somewhat sterile. It is practical and aesthetic to have some variation, and the director who identifies the occasional vowel or word that needs unifying will be satisfied with the results.
IV. Poor Vowel Shape
The mouth cavity is an important reasonator for the singer. When vowels are sung with the lips pulled
thin and drawn tightly against the teeth, they sound excessively bright and to lean towards flatness, because the mouth cavity is made smaller, and the mouth opening is small. When vowels are sung with the jaw dropped and with loose, more rounded lips, they sound full and reasonant, and lean toward in-tuneness, because the mouth cavity is larger, and the mouth opening is large.
When your choir is relaxed and is using adequate breath, no only will their intonation improve, but their agility, tone quality, and stamina will improve as well. By understanding and counteracting the causes of poor intonation, a director will lead his choir to new heights.