... I'm so completely flabbergasted that you don't know what I'm talking about that I'm finding myself at a loss for words. Besides that last sentence, which doesn't count. I was just sure this was going to be the thing that made it clear!
I didn't say that it doesn't sound like Leona. I said that she normally doesn't sing with a full, connected head voice, well, and she doesn't. The video might be limited, but it is nonetheless representative of what I've heard from her. I think one interesting thing about BZBlaner's vocal range clips for opera singers is that you can hear the difference between the lower register, the middle, register, and where the upper register starts. For instance, if you listen to Leontyne's I think you'll hear transitions at G4 (into her passaggio and into the middle voice) and E5 (where head voice starts), and G5 (where the upper register starts in earnest) You can hear transitions at about the same points in Sutherland or Nilsson's videos, too.
Of those examples you posted, only the first sounds similar in roundness and tonal quality to the Ave Maria clip. I'm not even sure what you were intending to highlight with the third, as there wasn't even something that was passable as head voice from the point you linked at, at least.
Those examples are mostly higher (Eb6s and C#6s), but I think even they are noticeable. I think the difference is particularly noticeable on lower notes, though. Falsetto aren't even equivalent ranges; falsetto starts significantly lower than head voice. For instance, Mariah regularly uses falsetto into the lower ends of the fourth octave; that's simply impossible to do with head voice. Of course, when falsetto is used that low it is necessarily very breathy and "spread" - but as falsetto goes higher, it increases in volume. This is likely the reason why male falsetto sounds so much louder than female falsetto does at lower pitches (e.g. mid to high fifth octave); men's voices actually sit an octave lower than women's do. This is actually a good explanation of the difference between undeveloped falsetto and head voice, though he uses "falsetto" to encompass both terms.
"The flexibility of the falsetto is shown to best advantage by the soprano voice, especially the the coloratura, whose naturally high tessitura includes relatively few tones in the chest register, and who sings almost exclusively in the falsetto. This is so, because by far the greater portion of the coloratura vocal line lies above the register 'break.'
In the absence of co-ordinate register action with the chest voice, the average soprano voice inclines toward lightness, flexibility and sweetness, while lacking solidity and evenly distributed power. This is true, of course, only if the falsetto is kept pure. Until such time as the chest register has been brought to a comparable stage of development, the soprano voice will remain weak and thin in the lower octave of the falsetto; low tones will frequently be inaudible and, although the singer is sometimes able to control piano effects, this virtue is largely offset by an inability to sing forte by way of contrast.
[...]As long as the falsetto is preserved in its pure form with a minimum of coordinate action with the chest register, it will present, in addition to being flexible, the widest possible extremes of intensity. Starting in the lower portion of the pure register (D, E, or F), the tone is at best soft, breathy, and incapable of swelling.
Ascending the scale, the intensity of the pure falsetto register mounts with increasing rapidity until by the time the top line of the treble staff has been reached a full forte has already been attained, after which the volume continues to increase until the very highest tones have been reached.
On all upper tones of the falsetto the singer is usually able to swell and diminish with fluency, but once the lower middle and lower tones have been reached this is no longer possible and the singer must be content to conform to the natural contour of the register outline until such time as the proper conditions have been established for increasing its volume. Once the register has been properly joined this vocal limitation is overcome."
In falsetto, the folds don't vibrate to their fullest capacity; there's a closed quotient of >40% instead of >50% as in chest voices. When you sing on a lower pitch, the folds are less contracted and more air escapes. This is what Mariah is doing when she's using falsetto in her lower-middle register. But as a vocalist ascends the scale, the folds begin contracting, air is forced through a smaller opening, and volume is increased naturally. You can hear this in action by comparing Christina's G5 with her G6.
hussy probably went to bed knowing I'd write an essay, too