Vibrato: What It Is and How to Develop It
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What Is Vibrato?
In vibrato, the voice is alternating subtly and very quickly between two pitches that are very close together. This periodic variation in the pitch (frequency) of a sustained musical note or tone should not exceed a semitone either way from the note itself. The effect is believed to add warmth to the voice.
Although vibrato is perceived as a pitch variant, it is discerned as a vocal timbre, or as an integral part of tone, evenly distributed over the group of notes, rather than as a pitch deviation. The pitch variance remains centered around the actual written pitch, and the listener automatically hears the average of the pitches being sung. Fully vibrant tone is squarely on pitch. When vibrato is permitted to take free-swinging pitch excursion, it actually acts as a centering intonation device. (It is more difficult to maintain exact pitch on a sustained note when singing in a “straight tone”.)
The parameters of vibrato include pitch excursion (oscillation), the temporal rate (cycles per second), and amplitude variance.
Although the purpose of vibrato is not completely understood, most voice scientists agree that vibrato enters vocal production as a relaxant principle because the body has a need for periodic muscle relaxation during heavy-duty or intense vocal activity, such as when singing sustained notes at high pitches. It is generally assumed to result from neuromuscular excitation of the laryngeal mechanism. Vibrato is the result of a balance between muscle systems in antagonistic relation to each other during phonation. When this balance occurs, the antagonistic muscle systems develop an alternating pulse that is a reflection of the continued energy level required of them to maintain equilibrium and muscular health. (Consider how muscles elsewhere in the body, such as those in our arms, begin to shake when strain or tension is prolonged. When we lift or hold a heavy object for a long period of time, we’ll often experience a periodic but constant shaking of the muscles that are being used.) In other words, the muscles of the larynx begin to pulse rhythmically in response to tension and subglottic pressure, and that produces the characteristic vibrato sound. It occurs naturally in order to protect the vocal folds.
The oscillations that occur in vibrato are the body’s reflexive response to mounting tension, and are believed to be the result of the healthy function of the vocal folds. The tension of the vocal folds is varied rhythmically, creating movement in pitch. Along with this tension change is a variation in the thickness of the folds.
Vibrato is not simply a function of the larynx. During the execution of vibrato, periodic oscillatory movements are also transferred to the tongue, epiglottis, and pharyngeal wall. This motion is a major component of the relaxation process that comes from coordinating breath energy with vocal fold responses. Even small movements of the tongue, epiglottis and pharyngeal wall may be transmitted to the external musculature of the neck. Therefore, a small amount of sympathetic vibratory action, discernible on the neck surface, is not necessarily problematic. (This vibratory movement is often more apparent in singers with thin, long necks and in those with prominent thyroid cartilages – an “Adam’s apple” - than in those with thick, short necks or with hidden or more deeply embedded laryngeal prominences.)
Tiny movements of the tongue and jaw – not likely visible to the naked eye - can also be detected in all vibrant phonation, and may be the normal consequences of the intrinsic muscles of the larynx. The tongue floor and jaw musculature are closely related, so external movement generated by the vibrato is transferred to the body of the tongue through the tongue’s attachment to the hyoid bone, and to the submandibular muscle system. Even proper laryngeal resistance to flowing air may produce small, externally visible vibratory movements in the neck, jaw and tongue.
Despite the small oscillatory motions of intralaryngeal areas, during vibrato, the basic position of the larynx remains relatively stable (unless a singer suffers from a wobble or tremolo).
My Philosophy On Teaching Vibrato
At the risk of being labeled a bad teacher, I will confess that I am an instructor who doesn’t teach vibrato directly - not unless asked about it specifically by one of my students, and definitely not until a student has developed solid breathing technique, good tone production and at least intermediate-level vocal skills. Although I’m certainly capable of teaching the skill, I make the pedagogic decision to place little emphasis on learning it for what I believe to be very good reasons, which I will explain in the following paragraphs.
First, it may partly be a matter of personal taste, or acoustical aesthetics. Although singing with vibrato can bring vitality to the voice and stylistic variation to a song, making the voice stand out at the end of a sung phrase, I tend to like the effect only in moderation, and prefer it to be very subtle whenever it is used. All too often, and mostly by untrained or poorly trained singers, I hear an exaggerated and induced version of vibrato being used. Many singers who develop these “false vibratos” tend to overuse them, placing them on every sustained note in a song and making them extremely pronounced. (The most extreme example would be Aaron Neville, who sings with a wide-swinging vibrato on nearly every note.)
Singers who apply pronounced vibrato to every held note in order to create excitement end up producing a sound that is just as predictable and boring as that of those singers who sing every note straight (without vibrato). These singers make poor stylistic choices, overusing the pulsating or oscillatory sound because they are under the impression that vibrato, or what sounds like vibrato to them, will convince others that they are great singers. As with drum fills, guitar solos and other vocal embellishments, though, vibrato is best when it is subtle and when it contributes to the overall sound of the song, rather than detracting from it.
Second, a poor understanding of what vibrato is and how it is achieved leads many singers to vocally produce poor, often unhealthy imitations of it. Many untrained or poorly trained singers expect to feel a certain sensation or to hear a certain sound that doesn’t necessarily always accompany natural or true vibrato production. They often have these faulty ideas because they hear the type of exaggerated vocal wavering and wobbling that many contemporary singers induce in their voices and come to believe that this sound and technique is true vibrato. Acoustically and aesthetically, these overly prominent vibratos are not the best sound. They are also generally not healthy ones, either. Unfortunately, these faulty interpretations of vibrato are often reinforced by bad singing teachers who both demonstrate in their own singing and teach to their students this false vibrato quality.
Third, placing too much emphasis on developing vibrato can create stress for the student of voice. There are dangers in approaching vibrato either as a necessity or as the Holy Grail of singing. Because many teachers place so much emphasis on developing vibrato, their students often feel it imperative, and are indeed often told that a voice without vibrato is not a good one at all, and then begin placing undue pressure on themselves to achieve this goal. Anxious to be considered a skilled singer, they usually end up imitating the sound of vibrato rather than producing it naturally and correctly, often employing unhealthy methods to create the “pulsing” sound of the voice. This pressure (both internal and external) to add vibrato to the singing voice often causes the student to rush ahead of his or her voice or abilities, and I think that this practice, especially in the teacher, is highly irresponsible. The voice needs to be ready, and solid technique needs to be in place first. Otherwise, the singer can only produce a counterfeit version of vibrato, typically through unhealthy means.
Vibratory sensations in the laryngeal region should not be induced or localized. In other words, vibrato should never be faked, created or forced. Many contemporary singers fabricate theirs through poor singing technique or learn to anatomically create a false version of it through teachers with incorrect ideas and knowledge about vocal fold function and how resonance truly works.
Contemporary teachers are more likely to teach vibrato as a “trick to be learned”, (e.g., by rapidly pushing in and then releasing the upper abdomen with the hands or by quickly quivering the jaw, etc.), than are classical teachers, who understand the importance of foundation work and who are therefore more willing to be patient when developing the voice. Many contemporary teachers don't teach or model patience to their students. Instead, they guarantee rapid results with their programs, and in order to follow through with this promise of immediate vocal success, they must instruct their students to take short cuts, such as using artificial methods of making skills like vibrato happen, rather than have them first do all the tedious foundational work that would naturally produce a healthier version of vibrato. Some methods of creating a vibrato when good technique is not in place are capable of causing strain and harm to the voice – something that no good teacher should ever permit or encourage.
Those singers who fake their vibratos do so because they have poor technique. With these singers, you’ll often hear wide, slow vocal “wobbles” or overly-fast “tremolos” that sound more like pitch errors than nice effects, and you will see tension in their jaws and tongues as they are forced to move up and down rapidly with the notes. Faulty technical premises contribute to a visibly oscillating jaw and tongue. (I’m not referring to the barely detectable sympathetic movements that may result from the connection between the larynx and the tongue and jaw.) Watch Whitney Houston as she sings in the movie The Body Guard, and you’ll see a perfect example of extreme jaw movement and tension. (This is sometimes called “the Gospel Jaw”.) She doesn’t have true vibrato, achieved only by using her vocal instrument correctly. Instead, she uses other parts of her body, like her wagging jaw and tongue, to help produce that pulsating sound and look. (Whenever I watch her, I can’t help but think that she makes singing look so much more difficult and arduous than it is. If that were really the case, I imagine that there would be fewer aspiring singers in the world.) Just because a singer may have a pleasant sounding or powerful voice, it doesn't mean that they are singing correctly or healthily. Many singers sound good in spite of their technical faults, not because of them.
While training tricks like rapidly moving the stomach in and out with the hands do indeed make the voice waver, they do not provide an accurate simulation of what vibrato feels like or sounds like, nor how it is naturally produced. They provide only artificial techniques that produce artificial sounds and results. These tricks go against what is natural and efficient.
Fourth, I don’t tend to teach vibrato to my students because many of them, through the learning of excellent technique during our lessons, develop it naturally in their voices without any pressure from me. This type of vibrato sounds natural and easy, and is a healthy product of good tone production, vocal fold closure and breath management. It is true vibrato that oscillates at the ideal, steady rate, and it can be beautiful. If teachers and students focus on developing balanced resonance and a warm timbre, the voice will become vibrant, and vibrato will become a part of it. When the voice is free and the student is relaxed, vibrato will appear spontaneously. Rather than seeking to create an oscillatory sound as their prime objective, singers should instead aim for a well-balanced timbre throughout the vocal range.
I guess that my philosophy is that vibrato is not something that should have to be “added” to the singing voice – it may be either suppressed or allowed at any given point, but it is a common misconception that it needs to be added to the tone, as it exists as an important element of resonant vocal timbre. When good tone production, resonance, placement of sound, breath management, as well as relaxation, are in place, vibrato naturally results, or naturally occurs, in the singing voice. It is something that our bodies do on their own, not something that we force them to do. Singers need only develop good, solid technique. There is no trick or short cut, like rapidly pushing the upper abdomen in and out with the hands, to make true vibrato appear before the voice is ready. It will come when all the other elements of excellent singing are present. (This may become a source of intense frustration to impatient singers who want to rush ahead and acquire this sound without doing the foundational work required to encourage its presence in the singing voice. They just want to make it happen, rather than wait for it to come.)
It is possible that your voice already has vibrato, but you may not recognize it because you are accustomed to hearing the exaggerated versions of vibrato that many poorly trained recording artists use or demonstrate. As Richard Miller, a very well respected international performer, master class presenter and prolific writer on singing, would say, “Don’t assist your vibrato; it’s already there.”