Tuesday, September 23, 2008

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Dear friends

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Thank you.


Friday, September 19, 2008

Spontaneous formant tracking: A point of logic, Part 1

Formant tracking is simply adjusting the vocal tract to a resonant state by attempting to match the frequency of one of the vowel formants to one of the harmonics of the sung pitch.

First, I will define the elements that we are trying to match.

The source: The sung pitch.

When we speak of pitch, we are not only speaking about the fundamental frequency that we are trying to sing, but the fundamental and its endless set of overtones. The overtones are multiples of the fundamental. For example, the pitch G2 (bass low G) is 100 Hz (or 100 vibrations per second). Its overtones would be 200, 300, 400, 500, 600, etc...

The fundamental is labeled F0 traditionally. It is also called the first harmonic or H1. The overtone above it is H2, the next one is H3 and so on.

The filter: The vowel (vocal tract)

Vowels can be defined by their first two formants, which correspond to the vocal tract divided by the tongue:


I altered the picture above to have the formant separation reflected. The red area is the first formant space (F1) and the white is the second formant space (F2). A picture of all the vowels can be seen here. I copied the page and include the picture here below so that you do not have to navigate away from the blog page:


I also include here the formant frequency values. Directly below is what is referred to as formant centers. These are the values given to the frequency pairs that give the most common version (some might say the purest form) of the vowel. They are color coordinated by vowel. The smooth column represents the F1 values and the dotted column represents the F2 values.


However, there is a wide latitude as to what the human ear will hear as a specific vowel in context. The following chart found at the National Center for Voice and Speech is a standard chart that has been used for years. It also shows were certain vowels intersect, that is where a formant pair might be perceived as two different vowels depending on context.


What we are attempting to do is to alter the size of the formant spaces to match the frequency of one of the harmonics of the sung pitch. This is the concept of vowel modification. The following chart which I've developed over the last year (there is one for each vowel spectrum, e.g. [o to u], [i to e], [E to ae]) shows the male passaggio up to tenor high B which corresponds to the female first passaggio and middle voice.


A larger version of this file can be found in PDF form here.

This chart tells us a lot. Before I go further, I must add that vowel modification (formant tracking) is most important where a precarious balance between the cricothyroid muscle and the vocalis muscle exists. Read the next blog entry which should appear in a couple of days for more details. For our purposes let us assume the muscular balance is not precarious.

The [a] vowel is colored dark blue on the chart. What is immediately noteworthy is that we do not see a lot of dark blue on the chart. That means that in the male passaggio and upper range and in the female first passaggio and middle range, a pure form of the [a] vowel is not the best choice. Keep in mind that neighboring vowels will sound like [a] in context when phonation is efficient (i.e. the quality of the vowel is strongly dependent upon a good phonation mode).

The problem in this range is a bigger problem for men than for women. We will discuss the female difficult range a bit later.

For men it is important to know that the range between C4-B4 is not only a problem of resonance (formant tracking) but one of muscular balance.

Many professional singers develop the crico-thyroid dominance that makes it possible to stretch the vocal folds for high notes regardless of resonance adjustments. Therefore, in the best case scenario, resonance tracking is a point of refinement. However, because accurate resonance adjustment takes pressure off of the vocal folds (see previous post on Inertial Reactance), a singer who experiences a precarious muscular balance would benefit from exact formant tracking. Most certainly a singer who has great muscular balance in general becomes a great singer when formant tracking is added into the mix. The voice would sound more consistently resonant and richer.

In the range between C4 and G4 the issues are different depending on whether one is a bass, baritone or tenor. This is because basses, baritones and tenors reach the muscular threshold at different point. The muscular change has been dealt with concurrently with the acoustic (resonance) issue. One of the points of this post is that formant changes sometimes occur before the muscular threshold. Let us take the different archetypal male voice parts one at a time:

1. Basso: Let us say that the muscular change (from vocalis dominance in the low and middle range to crico-thyroid dominance in the upper range) occurs on C4#. A basso will begin to feel the muscular tension around B3b or even A3. The question is whether at that point, the basso should try to access F1 tuning or F2. This brings us to how the singer alters the formant frequencies to tune to F1 or F2. The following rules come from the National Center for Voice and Speech and are scientifically proven and accepted as standard by the voice science community. more details on these rules can be found on the link directly above.

Four Rules for Modifying Vowels

1. All formant frequencies decrease uniformly as the length of the vocal tract increases.

The vocal tract length increases when the larynx lowers.

2. All formant frequencies decrease uniformly with lip rounding and increase with lip spreading.

Lip rounding and lip trumpeting have the same effect (see details on the NCVS page)

3. A mouth constriction lowers the first formant and raises the second formant.

This includes the raising of the tongue principally as in going from the [a] to the [i] vowel whereby the space below the tongue increases (lowering the pitch. Larger spaces have lower pitch) and the space above decreases (raising the pitch. Smaller spaces have higher pitch).

4. A pharyngeal constriction raises the first formant and lowers the second formant.

The reverse of number 3.

In order to follow these rules, we must establish what the default position of the vocal tract should be. I proceed from the following:

The larynx cannot fall to its naturally low position without the jaw being released. The laryngeal position that produces accurately resonance notes in the speaking range (male between 110 and 150 Hz and women between 220 and 260 Hz) should be the default. Therefore:

1. The larynx should maintain that basic low position.
2. The jaw should always return to the [a] position and the tongue and lips should articulate for all changes (consonants and vowels).

If the jaw had to close for vowels and the larynx had to rise, the variables would be too many and since both would narrow and shorten the larynx, the voice would take a thinner quality.

Given the parameters that I have established, the rest is a matter of logic. Let us continue with our basso on the [a] vowel:

C4 is an interesting note. The choice is either to raise F1 (the [a] vowel is the closest) or to round to [Ɔ] (as in "fort") to access F2. F2 is a better choice for the basso, but he is still in his lower register muscularly and might feel more "natural" (more speech-like) to sing the [a] vowel although the resonance might be imprecise and cause the tone to spread. C# fits the [a] vowel perfectly on F2. This is a moment where an F2 change might be better as mentioned earlier even though the muscular is borderline and the singer would still feel comfortable singing the more speech-like F1 resoanance. The vowel of the word "up" fits nicely to continue the second formant tracking through D4 and Eb4. Remember that to keep first formant tracking the lower space must become smaller. This means that the larynx may rise when tongue migration and lip spreading is not enough to accomplish the frequency rise. If the larynx is kept low during this change, it becomes difficult to match the formant with the harmonic in question (which is fixed with a given pitch). Some bassos are able to let the larynx rise and keep a first formant resonance, but they will lose the darker color, which is a basic characteristic of the basso voice type.

E3b is an interesting note. The same vowel (of the word "up") matches both formants. Some basses I hear round the vowel slightly which lowers both formants. This discourages F2, which needs to rise from its center (1180) to meet the 4th harmonic (1264) and lowers F1 from the center (640) to meet the 2nd harmonic (632). There are more options. It is possible that the singer might track the second formant of the schwa, [Ə] (1450), and by rounding bring it closer to the 4th harmonic (1264). It might be less exact but would diminish the competition from F1 since the first formant of the [Ə] (430) is out of range (too distant from the two relevant harmonics: H1 (316) and H2 (612).

In truth, either choice is possible. This is to say that while formant tracking makes for a more continually resonant quality, second formant dominance in the upper range is not as crucial for basses as it would be for baritones or tenors, unless the basso is singing F4-G4. The following graph (large version here) shows the E4b (D4#) as sung by two great basses, Nicolai Ghiaurov and Jerome Hines at "passar nelle tue tasche..." in the famous "coat aria" from Puccini's la Bohème.


The top spectrogram (using the Voce Vista software) is Ghiaurov and the lower is Hines. The green cursor goes through the dominant formant, F2 for Ghiaurov and F1 for Hines. Ghiaurov is clearly dominant on F2 which essentially means that most of the energy of the the sound gathers on the 3rd harmonic (H3). This acoustic "focus" has the positive characteristic of clearly delineating the harmonics and help increase energy in them and in the singer's formant range (between the two orange lines). The singer's formant range is the most sensitive acoustic range for the human ear. The Hines' spectrogram in this instance is less efficient. The acoustic energy is not only spread between F1 and F2 (although they look nearly equal, F1 is slightly stronger) but F1 lies between the fundamental (F0) and the second harmonic (H2) causing another spread of energy between those two harmonics. In short the energy is spread between the first three harmonics, which seems to weaken energy in the singer's formant range. The two Youtube.com clips in question are found below.

Both singers sound wonderful. However it seems my analysis of the chart bears out. Hines seems to favor a rather extremely low larynx. If the larynx was deeper than natural overall, the first formant would be tracked on D4# because the lowered larynx would lower both formants. That slightly depressed larynx it seems was enough to cause some balance problems between the two formants and suppress the strength of the harmonics to the point where there exact frequency is difficult to ascertain at sight. In other words, the acoustic adjustment of the vocal tract is out of phase with the frequencies of the natural harmonic series of the sung pitch.

The main point of this article is that maintaining a naturally low larynx promotes a natural transition from F1 dominance to F2 dominance. The next article will continue this discussion with analysis of the same range relative to baritones, tenors and female voices. I will also discuss the next octave which will deal with the female top voice.

© 09/23/2008 (Date of publication)

Monday, September 15, 2008

Deutsch, Español, Français, Italiano, Português (Swedish)

Teure Deutsche Freunde und Besucher,

Über Google Analytics hab ich gemerkt dass viele Deutsche den Blog regelmässig lesen. Obwohl ich möchte es gerne, ich habe leider keine Zeit den Blog zu übersetzen. Während meine Zeit in Deuschland war es mir klar dass die Deutsche sehr gute Englisch sprechen und lesen aber sind ebenfals sehr demütlich darüber. Vielleicht haben Sie alle ein bischen Angst auf Englisch über den Blog zu kommentieren.

Ich lade Sie herzlich ein auf Deutsch teilzunehmen damit wir können eine vollere Diskussion haben. Ich spreche kein perfekte Deutsch aber genug um Ihren Kommentaren zu beantworten.


Queridos Amigos de idioma Español,

He notado en Googles Analytics que muchos de Ustedes, visitantes del Blog, hablan Español. Me puedo imaginar que aunque Ustedes intienden perfectamente el Inglés que tengan miedo de comentar en un idioma estrangero. Lamentablemente de momento no tengo el tiempo para traducir el trabajo en Español. Sin embargo me gustaría abrir la conversación a todos ellos que quieren partecipar.

No hablo un Español perfecto pero bastante para comunicar con Ustedes. Los invito que partecipen de manera activa y que comenten en Español sobre lo que discutimos aquí para hacer la conversación mas profunda.


Chers amis francophones,

A partir de Googles Analytics, je découvre que beaucoup de Francophones suivent le blog. Le fait que vous y venez veut dire que vous comprenez très bien l'Anglais. J'imagine également que vous auriez peur peut-être de faire des commentaires dans une langue étrangère.

Malheureusement je n'ai pas le temps pour trauduire le travail, mais étant donné que vous y soyez, je vous invite de participer activement en faisant des commentaires sur ce que vous lisiez sur le blog. Ainsi la conversation sera rendue beaucoup plus riche et profonde.


Cari Amici Italiani,

A partir di Google Analytics ho visto che un numero notevole di Italiani seguono il blog. Il fatto che vi trovate qui vuol dire che capite molto bene l'Inglese. Io mi posso immaginare communque che voi non vi sentite comodo di commentare in una lingua straniera.

Purtroppo non ho il tempo per tradurre il lavoro ai diversi lingue che vengono rapprenstate. Io vi invito di commentare in Italiano sopra quello che voi leggete qui. Non parlo perfettamente l'Italiano ma abbastanza per potervi rispondere. La vostra patecipazione renderà la conversazione piu profonda.


Caros Amigos do idioma Português,

Eu observei no Google Analytics que muitos de vós, Blog visitantes, falam Português. Posso imaginar que, embora você intienden perfeitamente o Inglês que têm medo de comentar en esta lingua estrangeira. Infelizmente para o momento eu não tenho tempo para traduzir o trabalho em Português No entanto, gostaria de abrir a conversa para todos os que querem participar.

Eu não falam un perfeito Português, mas suficiente para se comunicar com você. Convido-vos a participar em uma forma activa e que comentem sobre o que discutimos aqui para tornar a conversa mais profunda.
To my many Swedish visitors, I wish I spoke Swedish. You are all a phenomenal source of information on vocal science. Thank God you all speak English better than most native English speakers.

Sunday, September 14, 2008

Appoggio. Response to a question on NFCS

The question that was asked by LCJ on NFCS:

When singers change teachers, this often means a change of technical direction. My current teacher is absolutely brilliant, sung on stages all over the world, and still in his mid 50's and able to sing "A mes amis" on stage after a 20 year career. I say these things as testament to his technique. Now, he's trying to teach me his technique, which focuses on the actual use of "appoggio". Before, my voice was basically developed in layers. My falsetto was oddly developed, and not blended to my chest voice going up. Now, there is MUSCLE MEMORY (I never thought I was going to say this here), that is majorly messing my stuff up. When I try to keep my throat relaxed and open with an "AH-UH" using my abdominal wall to support, when arriving to the E natural above middle C, my voice starts to crack. I would like to know how I can work on allowing the sound to just "flow" out starting at this problem area. My teacher is hardcore Italian school from what he's told me, and from what I know about Italian technique personally. So all you Italian Technique buffs, please help. Especially TS, and IT.

When I read your post LCJ I knew I was going to lose this whole Sunday afternoon to articulate this properly. I will attempt to define "Appogio" as completely as I can and then deal with your specific problem afterwards.

Appoggio: 1. from appoggiare which means "to lean on" as in "Io appoggio sul muro" I lean on the wall. 2. Also means to support as in "Io mi servo del muro per appoggio" I use the wall for support.

The first meaning is active. I am doing the leaning. The second is passive. The wall serves as support to my passive body.

In singing, the term appoggio has both a passive component and an active connotation among varying technical approaches.

In the best case scenario, breath-flow pressure becomes a self-sustaining system whereby the singer feels the breath pressure in the body as an influence of stability. The singer might say "The voice feels like it is sitting on something" like "a beach-ball pressed against the water in a pool". There feeling of buoyancy.

Others say that they consciously push down against the pressure of the breath. In that way they are actively trying to find something to lean on, to use as a support.

In any case, we are talking about breath pressure. Singing is not possible without breath pressure. So first we have to be able to create breath pressure. The primary pressure mechanism is the glottis. The vocal folds must close fully between 40 and 60 of the vibration cycle to create effective breath pressure (depending on what part of the range a singer is singing in). When the folds close properly, the desire to sing or to speak, activates the rise of the diaphragm and the contraction of the many abdominal muscles to create pressure. THIS IS AUTOMATIC. The singers job is to reduce pressure to a manageable level which includes two things:

1) Regulate volume. The strength of the laryngeal muscles to sustain fold length reaches a threshold when the singer sings louder than the system can handle. Some throats are stronger than others. With correct coordination, strength builds up over time and the singer can handle more volume than before. By desiring to sing softer, the abs and diaphragm activate less strongly and the pressure is less.

2) Pressure reduction by maintaining volume of the breath tank. By keeping the intercostals active, the singer keeps the space that the breath is in larger, reducing pressure. This active part (the singers only responsibility during exhalation) maintains the upper part of the thorax large. The diaphragm's rise and the contraction of the lower abs then become the principle agents of pressure. In this state of "muscular antagonism" (often called appoggio technique by modern pedadogues) many muscular actions are felt by the singer
in the pelvic area, lower back, upper back, below the sternum, etc.

Unfortunately, a singer, who feels these actions, begins to teach breathing by actively accessing these muscles. This is wrong!!! Those muscles respond automatically to the need to create pressure in order to create the sound that the singer imagines. There is no need to try to access these muscles directly. This need only presents itself when the glottis is not closed properly and there is air leakage. When the singer feels this loss of pressure (whereby the feeling of being supported is lost), then s/he tries to make up for it by trying to access these muscles. This only complicates the wrong coordination of the glottis.

Now, relative to your over developed falsetto and the cracking problem in the passaggio. This is a laryngeal problem. Singers are either vocalis dominant because of speaking habits or CT dominant because of the same. The transition point of the voice depends on balanced activity between those two muscle groups (the other muscles are second-tier and respond based on fold thickness determined by vocalis-CT balance). Oddly enough, I believe you are vocalis dominant. This means that your lower range (which is based on vocalis dominance over CT) is over developed. On any given note below G4 you use too much vocalis muscle. The folds tend to be a little thicker and the breath pressure greater. When you go to the top voice near G4 (for you around E4) you reach the pressure threshold for that particular fold length. For the folds to remain correctly lengthened for F4 the pressure must be reduced. Otherwise, the CT cannot handle the strain and gives up. Vocalis becomes more dominant and you cannot sustain the pitch level. The alternative is to go falsetto. In falsetto, the arytenoid side of the folds (the back side)opens up slightly a lets some air out. The pressure is reduced, the CT is able to lengthen the folds, but the resulting tone is lighter and breathier. Sounds real enough, but not quite.

The best approach I recommentd in your case is to sing softer in the middle range for a while, spend more time singing in the upper range to develop CT strength while maintaining proper function of the articulators (jaw released to neutral on every vowel including [i], larynx maintaining best low level [not depressed or raised], tongue and lips much more active in vowel and consonant production such that jaw closure does not alter the basic resonance of the vocal tract).

Over time, you will accomplish balance between the CT and vocalis and the folds will begin to close naturally and efficiently. This has been the gradual process of my own development as a tenor, and I have been following this approach with most imbalanced voices I encounter with great success. My personal case was the most extreme and now I can sustain a real high B4 and the passaggio is balanced. F and F# are still not perfect but significantly improved.

Stamina depends on the ability to maintain this balanced state under the pressure of a song. Tenor songs attack the passaggio incessantly and that requires strength. For that reason being able to sing an aria does not mean you are ready for a role. Being able to sing one page does not mean you can sing the whole aria in public under pressure. Being able to sing the high note really well does not mean you can sing it in context.

This requires patience and cracking. If the voice cracks when the principles of good singing are being applied, it means your muscular balance is not strong enough for that level of pressure. Sometimes the correct coordination cannot handle any pressure and you will crack any way. But by going through that period you strengthen the muscles and the voice is then able to sustain pressure while coordinating correctly.

Once that balance is achieved, the correct breath pressure is accomplished. Resonance adjustments help to create that self-sustaining system where the breath pressure is kept between 40/60 to 60/40 ratio of close phase to open phase of the each vibration cycle. The paradox of pressure/flow is then created.

I am sure you will have questions. So I am leaving the afternoon open while I work on my next blog post (a doozy that is taking some time).

© 09/14/2008

Wednesday, September 3, 2008

Liquid Focus or “Morbidezza”, a point of efficiency

The term morbide in Italian means literally soft to the touch. It is often used in singing to mean a tone that is not hard or muscularly tense. Recently I came up with the term “Liquid Focus” in helping a student experience the flexible efficiency of phonation. As important as empirical information is to singing, it means little if we do not have a way to communicate the implementation of such information.

As far as balance in phonation is concerned, the misunderstanding between the nature of falsetto and full voice is one of the most significant problems we have in vocal pedagogy. Little is possible without efficient phonation and achieving such a state is sometimes very time-consuming depending on what muscular balance or lack thereof exists in the given voice. Singers who sing with great flexibility and fluidity will state with strong conviction that full-voice feels like a continuation of what is referred to as falsetto or flute voice. Many others maintain that the increase of sub-glottal pressure that is necessary to full voice by definition means that full voice can never feel like falsetto. However efficiency as defined by scientists includes the concept of supra-glottal inertial air, discussed here before. SGIA confirms that in a resonant acoustic environment, the air above the vocal folds essentially acts as a facilitator increasing the length of the open phase and accelerating the close phase. In essence, the increased sub-glottal pressure is converted to air release increasing breath flow and therefore glottal amplitude considerably. In other words, the pressure that is built up during the short close phase is immediately released during the open phase. This exchange of pressure and release happens every fraction of a second. For A4 (440Hz, vibrations per second), this exchange occurs every 1/440 second. The resonant pressure-flow process results in a sensation of flexibility and softness that has been called morbidezza by the Italians.

The great problem with achieving liquid focus in our time is that the rushed nature of vocal pedagogy accepts the ability to sustain a pitch with enough carrying power to be a viable objective and that the ability to sing softly or flexibly is a special skill that some have by nature and others not. This kind of myth must be eliminated if vocal pedagogy is to recapture its original splendor. Teachers in Italy used to go to great pains and many years to achieve the kind of flexibility that results in the ability to sing for hours. This level of efficiency induces greater fluidity and viscosity and is consequently renders the singer’s work less tiring and more consistent. Stamina in singing is not so much an issue of strength in the large muscles of the body (although being well-toned is important to any activity) but rather to the balanced strength in the laryngeal musculature that makes the mechanics of liquid focus possible. To have the ability to sing like the great singers we must get our instruments balanced to the level that their instruments are. Those that begin with certain natural abilities have a difficult time believing that it should take disciplined and targeted work to get the instrument to behave efficiently.

Few singers exemplified this flexible, flowing, liquid tone as well as the great Catalan soprano, Montserrat Caballe. In the following clip of Signore Ascolta, she demonstrates the total control of her phonation by increasing her volume in the middle range at will, as at 1:10 on the word "labbra". Her approach to the top notes above the second passaggio is never aggressive even when forte. The final note demonstrates her amazing flexibility. The breath control for which she is so renowned would be impossible if her laryngeal mechanism were not perfectly balanced.

Her liquid tone is never compromised even at the softest volumes as in this breath-taken rendition of Strauss' Morgen.

On the men's side, there is the great Beniamino Gigli whose rendition of non ti scordar di me from the 1935 film that bears the same title. Gigli sings between pianissimo and mezzo piano, but it is clear that this is a voice that could crescendo to a big forte.


This ability to render a well-supported piano and better yet a messa di voce is very scarce indeed in our time especially among male voices. For that reason, I include here this excellent rendition of Lamento di Federico by the excellent Maltese tenor, Joseph Calleja.

© 09/03/2008