Why do singers use vibrato?

From: http://www.straightdope.com/mailbag/mvibrato.html

Hello, I have other things to add about this statement. You are correct about pretty much about all the technique involved in producing vibrato. The reason why we use vibrato in the musical world stems from a late baroque transition into the classical period. When vibrato was becoming popular on stringed instruments it was said by people such as Leopold Mozart (father of Wolfgang), “They (violinists) shake like they have the palsy when playing.” Playing/singing without vibrato nowadays gives the individual a hollow sounding tone. This is often used as an effect in twentieth century. Anyway, in the early classical period vibrato started gaining popularity, initially with stringed instruments. It has been found that playing with vibrato adds a more distinctive sound that is significantly easier to blend than playing senza vibrato. It was a natural progression from instrumental vibrato to vocal vibrato. It was one of the first instances of instrument to voice mimicry. Typically, earlier instruments were designed to mimic portions of the human voice. Certain styles like R&B and opera have an over-emphasized vibrato for the singers. As stated in the earlier response, operatic singers do this for projection and identification. Although I don’t typically listen to R&B, I assume this idea would translate similarly. Before the Classical Period, vibrato was not an effect that musicians and listeners found appealing. If vibrato is something that really bothers you, I would suggest listening to period performers such as Drew Mintor who is a wonderful countertenor. There are many performers out there who sing and play in the correct stylistic manner. I could continue talking, but I think I added some more information to this topic.

HUGS!
Sqrl


Gasoline: As an accompaniement to cereal it made a refreshing change. Glen Baxter

From my old “Physics of Music” class (ah the joys of a liberal education), I recall that the one thing that makes us think “that guy can’t carry a tune” is the lack of vibrato (or tremelo). About the only common factor found in the sound of “good” singing voices was vibrato.

It can be overdone, of course, but vibrato is necessary to some degree.


“East is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does.” – Marx

Read “Sundials” in the new issue of Aboriginal Science Fiction. www.sff.net/people/rothman

Well, I won’t say that SD entirely missed the boat here… there’s some good information, but a lot of misinformation as well.

The first thing they should have mentioned is that there is a distinct difference between the pop vibrato as exemplified by Whitney Houston et al. and a classical vibrato as exemplified by Luciano Pavarotti et al. The former is the conscious manipulation of pitch by the singer for effect. The fact that a pop vibrato is a conscious manipulation is what enables the singer to control the onset, frequency and amplitude of the variation. A classical vibrato, on the other hand, is a largely unconscious phenomenon and considerably more complex, involving the steady variation of pitch and intensity. This is the true vibrato, and any relaxed singing voice will tend to exhibit some kind of rhythmic variation in pitch and intensity. In fact, a big part of studying singing is learning how to remove all unnecessary factors from phonation so that the voice is heard in its true, uninhibited form. The natural human singing voice includes an unconscious vibrato. One of the easiest ways to distinguish a true vibrato from a manipulated vibrato is that neither the frequency nor the extent of a true vibrato may be changed. A classical vibrato is not something that is done or added, it is something that is allowed to happen.

Although we don’t exactly know what causes or regulates vibrato (it is likely that there are multiple contributing mechanisms at work) we do know that there seems to be a rhythmic variation in the activity of the major muscles responsible for phonation (vocalis, cricothyroid, lateral cricoaretynoid). This activity is sometimes accompanied by the rhythmic contraction and relaxation of adjacent related muscles and structures. Some people feel that such sympathetic activity is indicative of flawed vocal technique in an opera singer, but a survey of the opera singers will show that this phenomenon can be observed in even some of the most accomplished singers. It is important to note that these sympathetic motions are distinct from those in a pop vibrato where singers often induce and control the variation by manipulating the jaw, laryngeal position and/or airflow.

This rhythmic variation of vocal-muscular activity is necessary in opera singers because a static muscle is prone to malfunction, tension and related injury. The modern operatic style of singing uses the vocal apparatus so close to its natural limit that there is very little margin for error. Similarly, a stiff gait may be fine for everyday walking, but an athlete needs to be loose and flexible to avoid injury and perform at peak level. This is one reason why pop singers, even though they project their voices through electronic amplification, usually experience significant vocal decline and suffer from vocal injuries such as nodules and polyps, while these problems are far less common among opera singers who are actually producing much more volume with their own bodies.

Second, you got the dope wrong by suggesting that the vocal singers took their cue from the orchestra and added vibrato to their singing. The whole article seems to be based on the assumption that vibrato evolved from string playing, which is not the case. As I mention above, vibrato is the natural state of the singing voice and we can safely assume that singers were employing some kind of vibrato in their singing long before this practice was taken up by instrumentalists. Indeed, it is generally held that instrumentalists added vibrato to their playing in an attempt to better emulate the singing voice.

Finally, contrary to popular belief, vibrato does not help a singer to project sound into a large room or over a large orchestra. There are many things which allow a singer to be heard in a large room over a large orchestra. Believe it or not, part of this is volume – some rare singers really do have that much voice! However, the main reason you can hear the singer has to do with acoustics. Opera singers are trained to strengthen the acoustic energy of certain high frequencies (often called overtones) in the complex sound of their singing tone. This has two positive affects: First, these high frequency sounds carry very well through space. A listener in the back of an opera house is mostly hearing overtones. Second, an analysis of the sound of an orchestra reveals a range of frequencies with very little acoustic energy. As it so happens, the strongest part of the singing voice, the abovementioned high frequencies, fits right into this acoustic hole in the orchestral sound. So, the strongest part of the voice “cuts” through the weakest part of the orchestra. Beyond all that there is, of course, the composer. Good composers who know the voice write orchestra parts that allow the voice to be heard. Combine that with a sensitive conductor and the orchestra usually isn’t playing all that loud while the singers are singing.

I just want to back up slk’s arguments. I come from a family of generations of professional musicians, I minored in music at university, and I’ve studied classical singing for 5 1/2 years, with professional opera singers (said not to brag, but as evidence that I can speak with some knowledge on this). I have always and only heard that vibrato among instrumentalists originated as an imitation of the human voice. As far as singers go, vibrato shows that breath support is from the diaphragm and not the chest, that “placement” is correct, and that your vocal chords are relaxed (an absolute necessity if you’re going to be singing for four hours on stage!). “Placement” is rather hard to define (at least I’ve never heard an official, objective definition), but has to do with where in the body and head the singer “feels” the voice is located, and I’m sure has a lot to do with producing those distance-traveling overtones.
It’s perfectly possible for a classical singer to eliminate the vibrato (it just requires extra attention to breath control). It’s considered proper technique if you’re singing medieval or rennaisance music, or Gregorian chant, all of which were composed before vibrato became popular.


Lyxdesics of the lowrd untie!

Kara, slk, you guys wanna maybe show some evidence that vocal vibrato evolved from strings? Far from being the ‘natural’ state of singing, vocal music from Greek Music of The Spheres to Church Modes to medieval songs were always been performed without vibrato. In the Renaissance, as faux bordon became more widespread, ornamentation was implied by the music and left off the score, and trills and turns - only according to specific rules - were left to the discretion of the performer. However, even when performing Renaissance madrigals, ayres, chansons, etc., modern-day period performers omit vibrato, as this was not common practice even in those times. It’s really not until the late Baroque period, as SqrlCub mentions, that vibrato as a style was even commented on, not at all coincidentally the time of the emergence of opera, and stringed instruments.

Sqrl, you mention that performing senza vibrato gives one “a hollow-sounding tone”, and Chuck, that even in a music physics class this issue arose. I agree, but I maintain that this is just a preference of our 20-th century ears. Since we’ve always heard it that way, it sounds weird to us when it’s changed.

slk, as for your “unconscious” description, I can only say “bunk”. If you think Pavorotti gets on stage without being able to control every facet of his performance, much less know it’s happening, well, then I’ll sell you some nice ocean frontage in Saskatchewan. Sure, after years of practice, and with a sublime ear, and with a natural giftedness at performance, it may SEEM that this is innate, but don’t believe for a second that a singer of any caliber could not get up there and belt one out senza vibrato if axed to do so. Of course, controlling the vibrato, however it’s performed, is not the easiest thing in the world, but it’s crucial that a performer learn when to modify more, when less, in volume, frequency, and tone quality, appropriate to the music. Vibrato, after all, heightens dissonance, so anyone performing the music must know the difference between a G as a perfect fifth above C, a G as a major third over Eb, or a G leading tone into Ab. Just as each has a different proper intonation, each has a proper degree of vibrato, and a singer or player had better be able to control it.

As for “projection”, I never said it. A heavy vibrato, (said I), was “once necessary to make one’s voice recognizable in a large room, accompanied by a full orchestra”. The acoustics of the 18th century were pretty much hit and miss; in some halls, the only way to tell the cello and the tenor apart aurally was to listen for the “palsied” performance that Herr Mozart was talking about, as quoted by Sqrl above. This is where we get the school of vocal thought that leads to such immense tremolo as to actually be a trill, as commented on by the original question, and I included it because in past answers I’ve been criticized, much like “Dr.” Laura, for not actually focusing on the question at hand, and lapsing into a topic of my own choosing. See what I get for listening to you guys?

Almost forgot: since we did drummer jokes last week, here’s a singer joke:

Q: Why do so many vocalists die of exposure on front porches?

A: They don’t know when to come in, and they can’t find the key.

Ian, read my and slk’s posts carefully - we never said that “vocal vibrato evolved from strings” - just the opposite, in fact. Also, I’m a little bewildered by something in your post - are you saying that the Late Baroque period was “the time of the emergence of…stringed instruments”? What about the lyra, psaltery, and harp, used by the ancient Hebrews, Egyptians, Celts, Greeks, among others? And if you mean bowed stringed instruments, theyve been around at least since the 1200s (Medieval and Renaissance Music by Timothy J. McGee, U. of Toronto Press, 1985).

When slk said that vibrato was “unconscious,” s/he didnt mean the performer was unaware of it. Of course we can hear our own vibrato, and even feel it in our voice box. But it’s not produced on purpose. If it is, it’s a trill, not a vibrato. And I am in complete agreement with you that it is possible to “belt one out senza vibrato”. But singing senza vibrato requires extra control, conscious elimination of the vibrato, because the vibrato is a natural characteristic of the relaxed, mature (late teens onward) voice singing “bel canto”.

And please tell me where you get your information that the same tone in different keys “has a proper degree of vibrato”. That is completely new to me.

Here’s my favorite musician joke:
Q: What’s the difference between a bull and an orchestra?
A: The bull has the horns in the front and the ass in the back.


Lyxdesics of the lowrd untie!

Yes, I did mean “bowed strings”. That was pretty obvious from the context. By “emergence”, I meant, “emergence into prominence in contemprary ensembles”. Ibid. I understand you didn’t say that vocal vibrato emerged from strings, but I did. The evidence is manifest, in the literature and in contemporary performance practice of historical music. Vibrato is not used in medieval singing - not because it was unpopular at that time, but because it simply didn’t exist as a codified singing technique. As for ‘where I get my information’, well, in this case, it’s freshman theory and voice leading, most of which came from Bach, most of which came from God (theory joke). An open interval, say a perfect fifth, should be voiced as closely as possible to the mathematical intervals we all know. But, see, collapse that fifth, and all of a sudden you have a diminished chord, which you can’t hear until second semester. If your vibrato is too wide in frequency, you come to close to dissonance, and if your vibrato is too wide in amplitude, you lose the ‘constancy’ required for a perfect interval. Basic guideline - any time you have to alter a pitch’s intonation (3rd, 6th, 7th), you should heighten the tension with a more intense, more rapid vibrato. 'Course, this is in ensemble performance; in a solo, your vibrato’s intensity should vary with the phrasing, rather than with the pitches themselves, but still, there are obvious times when a more rapid or wider vibrato is called for, and times when vibrato should be placid or stilled altogther. I’ve taught, and received, entire 90-minute lessons where we discussed the necessary degree of tension for each note in a single phrase. And can you believe my parents think I wasted my time in college? However, this is, and must be, consciously controlled, and I’ve got to say in judging solo and ensemble work, I’ve found the indiscriminate use of vibrato to be a hallmark of IMmature performance. A performer can - and must - be aware of every facet of a performance, and to suggest that something this crucial ‘just happens’ is like saying Jason Williams ‘just knows’ how to throw a no-look pass.

Oh, wait, I see what you meant in the first paragraph. I meant to say, three messages up, “provide some evidence that string vibrato evolved from voice”. My mistake.

Look, Ian, I dont have the necessary
background to debate your points as far as
the production of vibrato on an instrument
goes - any instrumentalists want to
contribute? But it seems to make sense.
But vocal vibrato, at least among
classically trained (as opposed to pop or
country) singers is NOT DONE ON PURPOSE. It
is an integral part of the voice, and each
singer has a unique vibrato. If we do it on
purpose, it is NO LONGER CLASSIFIED AS
VIBRATO, but is a TRILL.

And having had a particularly anal theory
professor, I really appreciated the theory
class-Bach-God joke.


Lyxdesics of the lowrd untie!

Two more cents on the vibrato issue:

As a professional operatic singer, a teacher of voice, the holder of a doctorate in music, and a former participant in a scientific study of vibrato in the human voice, I feel I can offer the following:

  1. SLK’s summation of vibrato as it pertains to the classically trained singing voice is admirably close to the current state of knowledge in the field. Especially apt is his distinction between the “pop” vibrato, which is intentionally added for effect, and the operatic vibrato, which is an aspect of the singer’s basic sound—-the result of free, resonant and energetic singing (leaving aside for now those many operatic singers who sing with “wobbles” and other displeasing types of vibrato which are the result of technical or health problems).

  2. Ian is correct to point out that historical documents contain many references to the use of vibrato in singing, and that in many instances a “straight” tone was considered more pleasing. However, to extrapolate from that evidence that the presence of vibrato in the modern voice is a stylistic choice (rather than an naturally occurring phenomenon) is logically flawed. Any singer can straighten out their sound (remove the vibrato) if they want to, and many choral singers and early music performers currently do so as a matter of practice—-but this is an aesthetic choice, NOT a more natural one. The simpler sound that results from removing vibrato actually requires considerably more effort and muscular manipulation to produce. The fact that it may (or may not) have been stylistically preferred by singers hundreds of years ago is neither here nor there.

Allen Schrott

Ian, you seem like a very well intentioned and educated string player. But, with all due respect, your knowledge of the singing voice is not good. This is understandable and forgivable because you’re clearly not a singer, nor does it appear that you have studied voice nor the history of singing. Be that as it may, the article is wrong enough about the voice that TSD really should post a correction.

Before I begin responding, I’ll give a little history so that you at least know from where I speak: I have been singing professionally singe the age of 7 and am now a professional opera singer. This journey has involved over a decade of vocal study and a couple of college degrees along the way. Among my formal studies has been extensive work on the physiology and acoustics of the singing voice. Although my singing career centers around the Italian opera of the mid-nineteenth century, I have performed both baroque and renaissance opera professionally at one time or another. In so doing, I have worked with such luminaries as William Christie and the late Paul Echols, both of whom are considered leading experts on historical performance practice, especially as it relates to singing. Now back to the subject at hand…

Regarding the unconscious nature of vibrato, which I believe you referred to as “bunk.” Leading voice scientist Johan Sundberg says in his book, The Science of the Singing Voice, “Almost all professional opera singers develop vibrato without thinking about it and without actively trying to acquire it… The rate of the frequency modulation is generally considered to be constant within a singer. In fact, however, it is difficult, though not impossible, to change one’s vibrato rate by training; some singers are able to deliberately change their vibrato rate.” Learning to change one’s vibrato rate consciously is akin to learning to change one’s heart rate consciously. While they both seem possible, it is extremely difficult to learn and I don’t know anyone who can do either. So, it looks like it’s not bunk after all. Did you really think that singers using vibrato have to constantly think, “up-down-up-down-up-down …crescendo-diminuendo-crescendo-diminuendo-crescendo-diminuendo” to make the vibrato happen?

You also said that a “singer of any caliber” could “belt one our senza vibrato” if asked. This is true, although the singer would have to consciously suppress the vibrato. Furthermore, I can’t think of a single opera singer who would risk singing a top note full voice without vibrato. As I mentioned before, vibrato is indicative of a relaxed, healthy instrument. The stiffer musculature required for nonvibrato singing is more prone to injury, a risk that is compounded by the fact that “glottal resistance, and hence adduction activity, is higher in the case of nonvibrato tones (Sundberg).” It is the case that most any sustained note, whether sung by a trained or untrained mature singer, will tend to have some variation in both fundamental frequency and amplitude unless such variations are consciously suppressed. Ask any Broadway “belt” singer about this.

Because vibrato singing accompanies relaxed phonation, the presence or absence of vibrato also informs listeners about certain muscular conditions in the singer’s larynx. Indeed, “the vibrato is often missing when the singer runs into phonatory problems (Sundberg).” Sundberg further suggests that the presence of vibrato informs the audience that the singer is solving a difficult vocal task without a struggle, which is important for an aesthetically and artistically satisfactory result. If you think about it, nonvibrato singing often does impart a certain psychological tension, which is one reason why pop singers who are holding a long note usually break into vibrato (although a different kind of vibrato) at the end of the tone. This is an artistic technique of releasing the psychological tension that has been built by the long nonvibrato tone. Long nonvibrato tones that to not resolve into vibrato tend to seem tense and uncomfortable to listeners.

Now we get to the historical issue of whether vibrato singing evolved as an imitation of vibrato string playing or vice versa. You claim that vibrato singing was not used in medieval times because it “simply didn’t exist as a codified singing technique” at that time. While an even, regular vibrato is indicative of a good vocal technique, vibrato has never particularly existed as a codified singing technique. Even today, we don’t “teach” vibrato. In fact, there is very little that we know for certain about early singing. Unlike instrumental playing, very little was written about singing, and writers were unlikely to mention something like vibrato if it was considered a natural part of the singing voice. In the beginning of the early music revival, many people thought that historical singing was “straight tone” for several reasons. First, the straight-tone practice of Gregorian chant with which we are familiar is thought to be the oldest surviving vocal performance practice (although there is no reason to suppose that this performance style typified vocalism at large, and there is every reason to suspect that the Gregorian chant singing style has changed somewhat over the centuries). Second, as you mention, the emergence of vibrato string playing is well documented. Further, there is little mention of vibrato in what ancient writings on vocal technique we can find. It was also the case in the beginning of the historical performance practice movement that the vocalists singing early music were not exactly of the highest caliber (at that time early music was often the last resort of singers who weren’t good enough to make it in the standard repertoire).

That said, just because no one was writing about it doesn’t mean that singers didn’t use vibrato. As I said before, a relaxed singing voice will naturally have a vibrato – Sundberg backs me up on this. FYI, by vibrato I don’t necessarily mean the even, regular modulations of today’s trained singers, I just mean some movement in pitch and intensity. Note that most singers who are not suppressing vibrato like contemporary pop singers do have a certain quaver in their voice (think of the sound of an untrained “traveling minstrel” at a renaissance fair). This quaver, with a little training, can turn into a more regular modulation – but the presence of these small irregular undulations alone is enough to call it a vibrato tone. Given that a vibrato tone requires less effort and inflicts less wear ant tear on the vocal folds (per Sundberg), any frequently used singing voice will survive better by using vibrato. The singers who sang every day for Bach and in the Italian cathedrals would certainly have used vibrato tones or their voices wouldn’t have lasted. The same would be true (even more so) for an ancient Greek bard who sang lengthy epic ballads day in and day out. The vibrato was likely light and narrow because the singers weren’t singing all that loud (Sundberg says that the amplitude of vibrato undulations varies with the loudness of phonation; also note that the use and extent of vibrato for the voice and all instruments has increased in tandem with increasing volume levels). It is also thought that singers suppressed vibrato at certain times for expressive and stylistic reasons. This thinking is now becoming the prevailing idea of how the early vocal repertoire should be sung. Rising counter tenors such as David Daniels and Brian Asawa employ vibrato tones, as do most early music singers at the highest level. From my own personal experience I have never been asked to eliminate vibrato from my singing, even when working on early music with acknowledged experts in the field.

These facts, taken together, indicate that vibrato singing of one kind or another has existed as long as singing has existed. The fact that the use of vibrato in instruments emerged at a certain time in history suggests that the players picked up the idea from singers. Also, if you look at the time when v

One might also note that the “vox humana” stop of an organ is often ganged to tremolo, and that Bach is definitely on record as having used them together.

I can add as a semi-trained, semi-professional opera singer myself, I was, in a sense, “taught” to use vibrato – but only in the sense that I was taught to stop doing harmful things and sing correctly instead; the vibrato comes naturally when I am singing well.


John W. Kennedy
“Compact is becoming contract; man only earns and pays.”
– Charles Williams

Well, it’s getting pretty deep in here, isn’t it? Kara, if you’re unclear as to the difference between a vibrato and a trill, well, I guess that’s enough info on that. As for the origin of vibrato/when it was first employed/when it became popular, I don’t think we’ll solve here what many different historians can’t seem to agree upon. I think John W. gives a succinct clarification as to ‘natural’ vibrato; learning to strip one’s vocal technique of flaws and harmful practices, revealing the ‘natural’ voice underneath. Fine, you guys want to describe something that only emerges after years of practice and study as natural, I won’t complain. Meantime, let me close with a neat little quote I found in the Oxford Companion:

The guy who wrote that must have been a drummer.

Training – yes. But training of the “open your throat and stop straining and the notes will come by themselves” variety.

It’s like learning to lift heavy objects with your legs instead of your back. When you get it right, it’s actually easier.

And when you’re singing that way, the vibrato (and I agree that it’s a tremolo of volume and not any sort of trill, and so not the same thing that is called “vibrato” on strings) just – happens.


John W. Kennedy
“Compact is becoming contract; man only earns and pays.”
– Charles Williams

Probably it was a string player who wrote it. I would definitely say that the person who wrote that was likely not a singer, nor someone knowledgeable about the singing voice. If it is a singer, which I doubt, it is not a particularly well-informed one.

Allow me to quote a few things from the Oxford Dictionary of Music:

Tremolo: (It.) Trembling. In playing of string instruments, the rapid reiteration of a note or chord by back-and-forth strokes of the bow; also, on other instruments as well as strings, the very rapid alternation between two notes. Note that tremolo is the rapid iteration or alternation of notes whereas vibrato is fluctuation of pitch.

Vibrato: (It.) Vibrated. Undulation of pitch of a note… Not the same as tremolo.

These definitions directly contradict the passage you quoted from the Oxford Companion as well as the definitions given in the original SD article. Tremolo is not a variation in dynamic intensity, it is the rapid reiteration of a single note or a rapid variation between two close notes. Vibrato, on the other hand, is the variation of pitch around a central pitch. This is an important difference, because a vibrato tone does not go between two distinct pitches, it goes equally above and below a central pitch. The high and low pitches in a vibrato tone are unlikely to be actual pitches in the scale. To give an example, a C sung in vibrato tone doesn’t undulate between C and C# – the undulations are more likely to be a quarter tone above and below the C. According to perceptual research, what we hear as the pitch of a vibrated tone corresponds to the logarithmic average of the pitch undulations (Sundberg 1978; Shonle and Horan 1980; Iwamiya 1983).

So, I don’t know where the author you quote got his/her information regarding the vocal use of tremolo and vibrato, but it is simply wrong. Frankly, the word “tremolo” is rarely if ever used in singing. I have never seen this marking in a vocal score, nor is it commonly used in vocal instruction or as a descriptor of the sung tone. I love the way instrumentalists – yourself and the author you quote are good examples – who know next to nothing about the way the singing voice works will say that singers don’t know the basics of music terminology and the way their own instruments work, while at the same time insisting that the terminology and function of their own instrument is the “real way” even though it may be totally inappropriate to singing. The middle paragraph of your quote is nothing more than a piece of crap. I can hardly believe it was published. Just out of curiosity, which Oxford Companion did you use? There is the two volume, very expensive Companion to Music, but also the slimmer, cheaper Companion to Musical Instruments and Companion to Instruments and Orchestras. It would be slightly more understandable if the passage you used originated in one of the latter two books.

Regarding your remark to Kara on trill versus vibrato… In singing, a deliberate and prolonged alternation between two distinct pitches is called a trill. In a vocal trill the two pitches are recognizable to the listener as the high and low points of the variation. In vibrato, it is the central pitch that is perceived, not the high and low points of the undulation. Furthermore, in singing the trill is a conscious and manipulated variation of frequency while the vibrato is not. In this respect, Kara was not incorrect in her statement.

Then there’s the idea from the article – a idea to which you apparently still subscribe – that vocal vibrato is not a pitch undulation, but an amplitude undulation. At this point let me quote Johan Sundberg, a leading voice scientist, on vibrato in singing: “Physically, the vibrato corresponds to a periodic, rather sinusoidal, modulation of the phonation frequency… the vibrato [pitch variation] will cause the overall amplitude to vary.” The cause of the amplitude modulation is rather complicated to explain of one is not familiar with the acoustics of singing. I will attempt to paraphrase Sundberg: Each vowel sound is defined by several specific formant frequencies. A formant is a “peak” in the complex tone where partials at a certain frequency have greater strength than the surrounding partials. These areas of acoustic strength are created by the resonating areas of the vocal instrument, and they change as the vocal instrument changes parameters to form the various vowels. As a vibrato tone undulates in pitch, the harmonic partials move back and forth with respect to the formant frequencies of the vowel being sung. When the partials come closer to the formant frequencies in their undulations, the overall amplitude of the tone increases – the reverse happens as the partials move away form the formant frequencies in their undulations. So, as you can see, the fluctuation of intensity in vibrato singing is a by-product of the fluctuation in pitch. Indeed, the nature of the amplitude modulation differs according to both vowel and fundamental frequency. Sundberg weighs in on this issue, saying: “The perceptual significance of the amplitude vibrato is often overestimated. The main perceptual effect of the vibrato depends on the frequency modulation… The amplitude part of the vibrato is unimportant.”

I have to say that your author’s last remarks on the overuse of vibrato in twentieth century singing demonstrate a complete lack of understanding of the voice instrument as well as the history of singing. Does this author seriously think that an unamplified singer could produce enough sound to fill up a 4000 seat house without using vibrato for 90 minutes and have any voice left after that? If so, what an idiot. As I mentioned in my first post, pop singers regularly ruin their voices doing this even with the use of electronic amplification. Furthermore, the quote clearly shows that the author’s conception of vibrato is an instrumental one, not a vocal one (i.e., vibrato as an expressive device to be controlled and used selectively rather than vibrato as an integral part of the sound). Then the author tells us that vibrato’s use in singing may be due to a lack of diaphragmatic control or the tightening of certain muscles in the throat. (!?!) Well, we know that this isn’t true with scientific certainty. In fact, vibrato is more indicative of relaxation in the throat than tension. The fact that the author describes the use of vibrato tone in singing as a “fault” to which singers are “addicted” – which he/she further supposes confirms the earlier nonsense regarding misuse of the diaphragm and throat - reveals that he/she is not qualified to write on this subject.

As far as your idea that vibrato is something that only emerges after years of study and practice and is therefore not natural… you’re mistaken on several levels. Yes, a completely regular and even vibrato is something that does generally emerge after a certain amount of study. However, it is important to note that the singer at no time actually works on or practices vibrato itself (which I mentioned earlier in a quote from Sundberg). This is in stark contrast to instrumental playing where the instrumentalist typically spends a great deal of study on the production and regulation of vibrato. Again, just because the voice doesn’t immediately have a completely regular and even pitch undulation does not mean that the voice does not naturally tend toward some variation in the pitch of sustained tones. Indeed, the natural state of any muscle (with the exception of certain highly specific sphincter muscles) is fluctuation, not rigidity and tension. Since pitch in singing is determined by the muscular state of the voice instrument, it follows that some variation in pitch is natural. This natural inclination toward variation in pitch is, insofar as the vocal musculature is concerned, vibrato. Really, if you look at the development of phonation in an individual starting at birth, we have to learn to sustain discrete pitches because this is actually the unnatural thing (when males go through puberty an

?? If you look closer, the definitions are duplicates of (actually, they were the original source material for) what I said in the original article: “A true vibrato is, as you describe, a fluctuation in pitch”. This is standard terminology, but in some sources on voice, especially historically, the definitions of vibrato and tremolo are blurred, or switched. Anyway, I’m not really into argument by reiteration and ad hominem, plus the bulk of the argument is over things not appearing in the original question or answer, and also now I’m being told I said the opposite of what I actually said, and finally this is way too geeky a topic to get into a protracted flame war over, I think it’s time for me to let this one go on without me. Goodbye, cruel choral world!

Well I’m not going to get in on the debate, as I’m not a professional singer or musician (I studied guitar under the tutelage of a first violinist for the St. Louis Symphony Orchestra when I was a teenager, but that doesn’t count). I just wanted to say how interesting this post was to read and how much I learned.

I’ve always enjoyed singing for my own amusement - shower, car, occasionally with friends around a campfire, that kind of thing. But I’m usually too self-conscious if there are more than a few very close friends with me. Although I’m often told I have a nice voice, it’s completely untrained. And I never even contemplated voice lessons, as my mother used to ask me to shut up (not those words) when I was younger because she didn’t like my voice.

Little did I know until I read this thread that the “natural” vibrato I’ve been told I have is actually a good thing. I can attest to the fact that I wouldn’t know the first thing about how to make my voice do that on purpose. And I’ve tried to make it not do it, and it’s quite a strain.

Guess I shouldn’t have listened to my mother. Oh well :slight_smile:

Thanks for the very informative topic, everyone!


“The trouble with the rat race is that even if you win, you’re still a rat.” – Lily Tomlin

Well, I learned a lot too. I’m still
definitely at the student level musically,
and I know it. It may be geeky, but I’ve
enjoyed it. And now I have a few better
arguments than just reiterating that vibrato
is involuntary if this topic ever comes up
in conversation.


Settle for what you can get, but first ask for the world.
–Ka’a Orto’o, Gnomic Utterances C iv

Ian, you’re absolutely right that I misspoke on the definitions, and for this I offer my apologies. Your original definition for vibrato is right on. What I meant to comment on was your definition of tremolo as a “fluctuation of intensity or dynamics.” The rapid reiteration of a single note or the very rapid alternation between two notes does not strike me as something I would call a “volume shake.” In singing, tremolo is differentiated from vibrato by a less regular and more rapid modulation of pitch (Schultz-Coulon and Battner 1981). In this way, “tremolo” in a singer is a kind of inexpert vibrato and it is considered a vocal fault. The reason the term is so seldom used for the voice is that it is easier and more informative to describe it as an irregular vibrato that is too-fast – which is exactly how most vocalists would describe it. Usually this kind of vibrato is caused by some residual inhibiting tension in the throat musculature. It’s important to note that musical terminology is not the same for all instruments. There really is no vocal equivalent to the string tremolo because the voice instrument just doesn’t work that way.

As to whether I am arguing ad hominem (that’s “by attack on a person’s character rather than by an answer to his contentions” for the Latin-impaired)… I am truly sorry if you feel that way, but I don’t think that’s necessarily what I’ve been doing. What I have done is present voluminous amounts of hard scientific information and briefly comment after the fact on your apparent unwillingness to concede that your first take on the subject may have been mistaken. This is not a subject in which it is possible to “agree to disagree” – one is either right or wrong.

Let me give you an example of what I’m talking about: Suppose I, a singer, had been writing an SD Mailbag answer to someone who asked: “what’s the deal with string players shaking their left hand all the time while they’re playing?” Part of my answer, based on my singer’s conception of vibrato, might have been that a skilled string player’s vibrato is constant in both frequency and amplitude at all times. Further, let us suppose that several points in my writing on string vibrato were equally flawed due to my approach from a singer’s perspective (I might say, for example, that string players seem to develop vibrato over the course of training without ever working specifically on it, etc., etc., etc.). Then a day or so later… you, an experienced string player, post a detailed response pointing out my many mistakes, including the fact that skilled string players consciously manipulate the rate and extent of vibrato all the time for reasons of style, expression, tuning and harmonic function. I might be surprised to find out that string vibrato didn’t work the same way or under the same set of principles as voice vibrato, and I’d proceed straightaway to a string professor or other professional to clear this up. My next course of action upon discovering my mistake would be to contact the SD powers-that-be about running a follow-up to the original article with the correct information. On the contrary, not only have you done nothing of the kind, but you have rejoined with sarcastic remarks (i.e., your offer of Saskatchewan ocean frontage, your remark to Kara about trill versus vibrato, etc.) and have intimated that singers don’t know correct musical terminology nor how their instruments really work. Again, I’m sorry if this colored the tone of my responses… but put yourself in my shoes. It isn’t a coincidence that none of the singers who have responded agree with you.

Getting back to the original article, your points on the voice were these:

Point: Historically, singers began using vibrato to imitate strings which were already using vibrato at that time.

My response: Vibrato is a natural phenomenon of the relaxed singing voice, and all mature voices have a tendency towards some fluctuation in the phonation frequency of sustained notes. Therefore, it is highly unlikely that singers started this practice by copying string players. In fact, it is generally accepted that instrumental vibrato evolved in an attempt to imitate the singing voice. For example, it is not a coincidence that (changeable) string vibrato rates just happen to be the same as (unchangeable) vocal vibrato rates. Since the prominence of vocal vibrato increases with volume, it is not coincidental that instrumental vibrato began to be used at a time when volume rates increased, nor that instrumental vibrato has increased in rate and extent as singing has become louder over the years. Furthermore, the idea of vibrating the pitch of a sustained tone had to come from somewhere. It is infinitely more likely that the idea came from an instrument that naturally displays this phenomenon (the voice) rather than one for which vibrato is not natural (strings). All the above has been extensively documented and supported.

Point: Vocal vibrato is not a fluctuation in frequency (pitch shake), but a fluctuation in amplitude (volume shake).

My response: Vocal vibrato has both fluctuation in pitch and intensity. However, pitch fluctuation is the important defining element. Indeed, the volume fluctuation in vibrato singing is an acoustic by-product of the pitch fluctuation. All the above in this point has been extensively documented and supported.

Point: Vibrato was once used by singers to acoustically differentiate the vocal sound from the sound of the instruments.

My response: There is no evidence that this is now or has ever been the case. In fact, there are many acoustic reasons why the voice is perceived as distinct from the orchestra. Changing vowels and consonants are definitely important in this respect, as is the acoustic phenomenon where an area of high acoustic energy in the trained voice coincides with a relatively weak area in the orchestral sound. I have described this last effect in some detail.

Point: “Volume shake” is used by singers for effect as a stylistic device.

My response: As demonstrated above, it is a pitch shake, not a volume shake. If you’re talking about vibrato (pitch shake)… for pop singers, this is true. For classical singers, vibrato is an integral part of the tone.

Point: Use of vibrato by singers obscures the pitch.

My response: Not true. Listeners have no trouble accurately assigning pitch to vibrato tones according to the logarithmic average of the pitch fluctuations. Further, vibrato tones are much easier to tune. Both these points were extensively supported with scientific evidence.
These points lead directly to the question of whether vibrato is conscious of unconscious, which we have been discussing. There are, as I mentioned earlier, two distinct kinds of vocal vibrato. A pop vibrato is consciously produced and controlled in terms of rate and extent via manipulation of the jaw, laryngeal position and/or airflow. A classical (“true”) vibrato, on the other hand, is present at all times and is not consciously produced or controlled by the classical singer in terms of rate and extent, except that it can be eliminated with conscious effort. This is because the true vibrato is an innate neurological/muscular phenomenon of the voice instrument. You have, up to now, refused to concede on this point even though I have conclusively and exhaustively debunked every argument you have made for a consciously controlled vibrato. Even now, after I have provided mountains of information, you are still refusing to concede that you might have been mistaken about the voice in your article. Rather than do this, it seems to me that you’re to getting yourself out of the hole you dug by deciding to take offense and run away from the discussion. Frankly, I don’t understand why I have to prove this. I’m a singer. You’re not. The fact that everyone seems to be agreeing with me should tell you something.

I’m not trying to be mean here, nor was I previously. But, Ian, it seems to me that the best thing to do when someone (or several ones) with greater authority on a subj