Often, a singer will come to me and ask me to teach him to sing piano. The strange thing is that the singer often has the ability to sing a well-coordinated piano but does not realize that s/he has the ability. Our classical singing world is so driven by volume that quality is often sacrificed for it. The terms falsetto or flute voice are very misunderstood and are often so named because the singer does not yet have the ability to sing such notes with enough breath energy (sub-glottal pressure) to match the quality of the the lower voice that they summarily accept as their “real” voice. In many such cases the real voice is in fact a “pushed” voice. In other words, a voice sung with too much breath pressure, forcing the vocal folds slightly apart. In such cases the voice sounds loudly up close but because of the lack of efficient fold closure, the resulting harmonics lack in power and the voice is not heard well at a distance or with orchestral accompaniment.
Very often we hear lighter voices sounding much more present than their fuller voiced counterparts, yet the fuller voices are called more dramatic, more powerful than the lighter voices. The darker sound we associate with dramatic voices is indeed a natural characteristic of such voices. However, it is important to distinguish between a sound that is rich and has dark qualities even at its most efficient and brilliant and a false darkness that come with “loose” phonation (inefficient fold closure).
It is important to remind that the world record holder for the highest note sung is a male and he sings C#8, a half step beyond the high side of the standard 88-key piano. This would suggest that a woman could theoretically coordinate pitches in the vicinity of C#9 since male and female voices average around an octave apart.
The greater error is however the misnomer “falsetto” applied to soft high notes that cannot handle a great deal of breath pressure. I had an F6 even 20 years ago that was referred to as “reinforced falsetto”. As I train as a tenor, I am finding that those notes have come back and they are becoming stronger. This I have also noticed with coloraturas I teach. Over time, what used to sound like a flute voice becomes gradually fuller (what some might call “real”). In short, what is often called “not real” or “falsetto” is rather an undeveloped sound. The coordination required for each individual note necessitates a specific recruitment of muscle fibers. See a simple discussion of muscular motor units here!
The ability to coordinate the two main pitch muscles (Vocalis and CT) on an individual note does not mean that the muscles are able to exhibit the same strength on even an adjacent note, one half-step apart. An individual note depends not only on increasing muscular activity of the more dominant muscle (CT for high notes, Vocalis for low notes) but also decreasing muscular activity in the more passive muscle (Vocalis for high note, CT for low notes). The strength of motor units in each of the muscles factors in. The strength of the required muscular motor units must be high enough to resist the breath pressure applied to the system (i.e. volume). The question therefore is whether the system, correctly coordinated relative to necessary motor units in each muscle, is strong enough to handle the applied pressure without the system buckling and recruiting additional motor units that are not appropriate for the note in question.
For example, if a tenor is trying to sing B5 and has a vocalis recruitment that is appropriate to Bb5, the pitch will either lower or the folds will loosen (i.e. relaxing the Inter-Arytenoids that close the posterior end of the folds. I.e. Speeding up vibration cycles to maintain pitch). The result would be correct pitch but with a kind of inefficiency that prevents the note from sounding brilliant and present.
What often sounds like a light sound is often a correct muscular set-up that has not yet gained enough strength to handle the necessary breath pressure that would result in a note that sounds “real” (i.e. matching the quality of other notes that are strong in the range).
In short, forcing a note to sound louder before its time will change the natural set-up of that note. To develop notes that sound weak, a singer needs 1) to accept the notes as weak and challenge them carefully by applying a little more volume until they develop in strength. This might take time but it guarantees the correct coordination of the laryngeal musculature.
Increased sub-glottal pressure can also have another effect. It could induce hyper-activity in the Inter-Arytenoids causing pressed voice. In such a case, folds thin out and are pressed to maintain pitch (i.e. slow down the vibration cycles). This is often the case with Counter-Tenors who often apply more sub-glottal pressure on very thin folds than the muscular set-up can handle. Over time, the hyper-function of the IAs cause a reduction of sound pressure (volume) lowering the quality of the sound. Counter-Tenors often start to sing big repertoire (for them) too early. The extreme light mechanism of a traditional male voice requires a long time to develop enough strength to sing Handel Castrato roles in large Opera Theaters with large orchestras. The tendency is to press the lower octave of the Counter-Tenor’s range in order to match the thin but relatively intense sound of the upper octave. It is not unusual that the quality of Counter-Tenor voices that specialize in Opera, with large orchestras in large theaters, lowers significantly over about 10 years.
Several issues need to be reviewed.
1. What we call falsetto and flute voice is usually a weak but properly coordinated upper range that needs to be encourages and challenged carefully in order for it to develop into a full sound.
2. The lower and middle voice, often called “real voice” is often inefficient production with fold postures that are too deep resulting in looser adduction.
3. Volume must be applied judiciously in order to maintain a muscular motor unit recruitment mode that is appropriate to the note being sung. Too much volume applied too soon (i.e. singing roles that require great volume before the singer has properly developed) can ruin the quality of the sound and hinder the progress of the singer.