Re: Differences in falsetto and head voice.
(Martin & Beyondtenor, I believe this is the answer to your question, according to Mary Beth... she would seem to suggest that incomplete closure in the chest voice is NOT referred to as "falsetto"... I would tend to agree)...
Yes, I understand and I actually use "flageolet" in my pedagogy to describe the highest head tones, but admittedly, I dont think its the best term yet... Im still developing that... These are not some invention of SLS but are common terminology in vocal pedagogy. Read Richard Miller, William Vennard, Johann Sundberg, Ingo Titze etc. Once the CT are no longer able to stretch and thin, something amazing happens called dampening, whereas the actual vibratory length of the vocal folds shorten. This happens in the extreme range of head voice for both males and females in those voices who are able to registrate in a balanced manner. Well, since Im in direct communication with Titze these days, Ill look into that.
I am reading
Vocal Health and Pedagogy, Vol. I
Science and Assessment
By: Robert Thayer Sataloff, M.D., D.M.A.
Vocal function does not always remain the same... it depends on what techniques and skills you teach. A body builder and a power lifter do not utilize the same muscular functions entirely.. they are specialists. Opera singers generally sing with a more lowered larynx, this is functionally very different then pop singers or what I teach. And pop idol singers dont usually sing with thyroidal tilt, head voice adduction and sub-glottal velocities consistent with progressive metal singers, for example. You can train the voice to do different things, to make specifically different kinds of sounds... CVT and Estill are but two schools of teaching that further confirm my point that the voice or Larynx (Estill) can be "configured" in different ways for different sounds.
Part of my challenge with the "SLS" legacy is this insistence that the voice has to homogenized, "balanced", neutral laryngeal configurations at all notes of a singer range & registers... and that this is the ideal set-up for every singer.
I invite you to view my "bridging & connecting" videos on this forum... when I sing these high velocity, sub-glottal, twangy head tones... its doesnt feel like "speech level"...
In regards to eating humble pie... I totally agree!!! We have discussed this before on this forum... the best voice teachers today are the ones that can eat humble pie from time to time... I think I have done it myself a few times on this forum... The courage to be able to admit that your not correct on something or that you need to learn more about something is one mark of being a great voice teacher.