Vibrato, an even tonal oscillation of the pitch center, is a natural phenomena of free and beautiful singing. It is the most accurate barometer of correct vocal production, and is the result of the healthy function of the vocal cords. Vibrato adds shimmer and movement to the voice, and is heard as an integral part of the tone, rather than a pitch deviation.
Excessive, slow vibrato
Excessive vibrato (slow and wide) is commonly called a wobble. It usually results from slackness of the vocal folds due to insufficient resistance to airflow. Thus, the entire voice suffers from overweighted or overblown production. This undesirable characteristic often appears in aging singers when muscle tone lessens, but it frequently happens to younger singers as well. However, we know that if one sings correctly, the voice can remain healthy and vibrant for life!
A wobble is usually a support problem (not enough lower body resistance of the upper and lower abdominals and the lower lumbar muscles to hold back the breath pressure), followed by carrying too much weight too high in the voice (singing with too much “thick vocal cord mass”), lack of focus in the tone, and lack of proper closure of the vocal cords.
The good news is that a wobble is generally easier to remedy than a tremolo (overly fast vibrato, like a bleat) or straight tone (no vibrato). (1) The first question should be that of support to allow the lower body resistance, leaning gently outward (appoggio) , to hold back the breath pressure. This allows for a healthy stream of air through the larynx, and frees up the throat muscles. Often you will see singers’ entire vocal musculature (jaw, tongue and larynx) shaking with the vibrato. This is a sure sign of imbalance, whereby the throat and neighboring muscles are pressured in creating the tone. Exercise (simple and easy): Inhale, taking a low breath, and exhale on an “s” or hiss. You will immediately feel the “support muscles” engage to fuel the fine stream of air. Keep this same resistance when you sing. Remember, we do not hold our breath when we sing, nor do we blow it out! The air disperses in a fine stream through our nose and mouth only when we use proper lower body resistance or compression.
(2) The second question would be to check that you are not overweighting the voice (trying to sing too “big”), or carrying the heavier, lower mechanism too high in the voice. This also causes intonation problems, with the pitch going flat, and lack of upper overtones. Make sure that your vowel slenderizes through the second passaggio because it is often after this second bridge that the overweighting and wobble get worse. Be sure that you are slendering and making the vowel taller, still remaining connected to the lower body, and not squeezing or slenderizing the throat! Exercises: (a) Descending scales on an “u” vowel, blending the higher, lighter mechanism into the lower mechanism. The Old Italian School teaches that the “u” vowel must be in the center of every tone. (b) Ascending five and nine tone scales, and arpeggio exercises on the closed vowels “i” and “u”, making sure that the lighter mechanism is activated in the upper voice, while keeping a balance of depth.
(3) The third question should address focus in the tone. When the tone is unfocused, it is related to overweighted production, which was just discussed. Once again, are you trying to sing too “big”, forgetting that the voice is an acoustical instrument? When support, air flow and resonance are in balance, the voice will carry and get “big” on its own. It is carrying power that is most important! *Note: Make sure that you are not depressing the tongue, but rather be certain that you keep the gentle arch as in “ng”. A depressed tongue is a major cause of singing flat because it causes the soft palate to fall. Also, the pressure at the root of the tongue can be a major cause of the wobble due to the direct pressure it puts on the larynx. Exercise: Any descending or ascending scale beginning with “ng” and opening up to a single vowel, starting with closed vowels first. When these are focused and ringing, then you are ready to practice on open vowels. Your goal is to keep the “ng” ring through your cheekbones throughout your singing, with the fine stream of air through the nose and mouth.
(4) Question number four is whether or not you are beginning the tone with the lower support muscles (sometimes called grunt muscles) and keeping them engaged. Once again, this comes back to support, which controls the air pressure and encourages the vocal cords to come together efficiently. If your onset is poor, the rest of the phrase will undoubtedly follow. Make sure you begin the tone with an impulse from the upper and lower abdominals and lower lumbar muscles.
As was stated, healthy vibrato is result of healthy, coordinated singing. When the support, airflow and resonance are in balance, the vibrato will take care of itself.