One of the fundamental points in technique is when and with what position making the  copertura, especially related to the first turn of the larynx for the first bridge. Great part of national schools and national taste in sound is given by this position and way of making the copertura. If you prefer you can think about it as the first point in which you make the turn of the larynx, being the second the necessary one to obtain the high notes in female voices, falsetto in men and a certain kind of  successive slightly turn for high notes in men voices while sustaining when it is not desired a falsetto sound.
It gives the clear and precise english sound in medium and medium high register with its quite high position and the habit of not getting below, the somewhat flatted and falsetto sound in France, the velvet and lightness of accent and high tones in the spanish due to the involvement of soft palato to obtain their copertura, the always connected to sustain and back of american school that gives more strenght to the nearly same position then english school but less poetry in the ovetornes, the low position in german school that need to put some intubation to make the turn possible and connected, the perfect balance of all these elements in Italian belcanto school, the slightly below positions of the swedish italian belcanto that gives more weight by the lower position and greater use of back diaphgragm connection, the russian school which now is the closest to the XXth century italian belcanto we have.
The first turning point can be moved and managed both by pronounciation or use of mask muscles and soft palate or internal nose muscles and the sustain and appoggio muscles and the posture in itself. It is something to think about when starting a training and also it is to have a strategy about according to repertoire and market in which the singer is working or going to work.

For a singer or a performer it is often more effective looking for vocal solutions thinking in a way that has a vocal logic instead of a truer one. We have a point of acting to obtain the voice so deformed by instrument way of being built and related and cohordinated and the fact that we are inside that we have to accept and make allied this deformation. The vocal correct gesture acts in all its possibilities only from a vocal way of perceiving and thinking; if we know that well we don’t need to make confusion bewteen what and how we think to sing and how we really act to sing.

There is only a way of being appoggiati and sostenuti, and it depends on a certain precise connection between diaphragm and larynx. You can hear it in a certain kind of overtones for the sustain and a related way for the appoggio, being that relation perfect when you can correctly execute a messa di voce (from pianissimo to forte or fortissimo and back to pianissimo). The way you perceive them and where you feel in the body depends on style, vocal range, individual body and body specifities, technical level (the higher level pass from a point of similarities of perceptions). All the places everybody can feel must work during the correct vocal gesture, so often in the training we have to work what you will never feel while singing, because it is the balance of all the places of diaphragm insertions with some wanted overacting that make the correct appoggio and sustain for style and voice.
On this subject one of the more common mistakes is to overwork the insertion you want to be heard in the sound, without noticing that it is the lack of some others that make its work not satisfing, the second being the fear for the overdoing of some specifics and the choice to make every voice simply and prudently just balanced without any specifics (losing in that way what of personal and truly specific a voice can produce in a deeper level).

One thing that has been a defeat to classical singers and teachers, and still persists as an issue, is the comprehension of musical and sound requires by voices used for contemporary purposes and t…

Source: On contemporary voice / Sulla voce non “classica”