I understand that falsetto and "voice head" are different things. And most important, falsetto exists only in male voices. And "breaking your voice" is still another one. Let's try to explain:
- Voice head, as mentioned before, is the normal sound of the voice, male or female, in high notes, as the head resonance chambers get stimulated. The trained singer can force the bottom of that range two or three semitones up or down. This sound is not falsetto. This is the voice of tenors in the high notes (aprox. from F), and counter-tenors, and the female voices of alto and soprano, at their high range too (aprox.F, one octave above tenor). Male voice of bass have a range considered "head" too, aprox. from D.<>br>
- Falsetto in men: used by some singers (wrongly named counter-tenors, could be named more correctly "falsetteers") playing the part of female altos, this is still pretty common in English choirs which follow the "all-male" tradition. I personally don't like them. It is obtained by relaxing the position of the larynge and allow the nose resonators to take the most relevant part. Curiously, basses get the best falsettos, and many tenors can't obtain this sound. The sound seems (not surprinsingly) false, forced, not authentic. Some mexican singers use this as an ornament, and german singers from the Alps region use it in a fast alternation with head voice to obtain weird effects. Not used in classical music except the mentioned male-Alto parts. There is a technique called "reinforced falsetto" which some singers have learnt to master, with very good results, almost indistinguishable from counter-tenor voices, but I'm afraid it is dangerous for their vocal health.
- Falsetto in women: Many experts say that it does not exist, because the position of all muscles and cavities in women is already close to falsetto when using the head voice, also called a biphase-voice. Some authors consider falsetto as another sound beyond bi-phased and call it three-phased voice, however it is neither used in classical pieces, though we may find some effects in jazz and blues singers who use it as an ornament. Anyway, no serious vocal pieces are written for falsetto.
- Break of the voice: This is only allowed to the singer Shakira, and possibly others, because they are physically beautiful and generously show breasts and bellies (which is a respectable art too). I personally could attend to their show with good earplugs, if somebody else pays the bill. (Sorry, it's a joke - many people like them). Anyway, no classical teacher will allow you to even think in this technique (or lack of technique) because it breaks the melody, which is a fundamental part of any vocal piece.
- Yodeling : I know nothing about this.
- Escamillo's technique : any voice, but good anti-slippery shoes and black clothes, for a fast escape from the stage when necessary.
Un abrazo - Andrés