Moving on up

Someone asked: “Why do voices tend to move up as we get older?” The questioner wonders if mezzos turn into sopranos and baritones into basses as age comes on
I don’t think they do. In my opinion, most voices ARE already high. As most women are sopranos, I suspect most men are tenors. I have no scientific evidence for this whatever. My feeling is based on my years of teaching and the percentages of high and low male voices that have presented to me. I now have seven male students and five are tenors, and that is about how it has always been. So, it would be common, when they start to study singing, for baritones to shift to tenor because they were never really baritones in the first place. I think it is less common for women to move up because we have the advantage of singing above the passaggio a lot and don't need to learn how as often as men, so our voices tend to find their right place more easily. These remarks do not mean, of course, that there are not true baritones, basses, mezzos and contraltos. Certainly, there are. It's just that a lot of voices are not what their owners think they are. This is a matter that takes a good deal of work to free the voice and let it reveal its nature. That is what I tell my students. "Let us work on the voice and allow it to tell us what it wishes to be." It can be a lengthy process.

So as far as voices moving up, assuming that the vocal training singers are getting is good, it would be normal for voices to move up. The better a singer's technique, the more tendency to move into higher ranges. Of course, this implies I am right about most people having a high voice.
Having said that, yes, a voice that should "move up" (or down as the case may be) MUST do so. One cannot stay in the wrong voice type without damage, whichever way it should move. Understand that there are two issues. One is range and the other is tessitura. It is not just how high or low you can sing, but where does your voice feel most comfortable spending most of its time. There are mezzos (ex. Bartoli) and even contraltos (ex. Podles) who have very high notes and sopranos who have lots of low notes. When I was young and a lyric coloratura, I had a B-flat below low C. Always had this extension. Go figure. I have a couple of tenor students who can sing way down in the bass range. Every voice is unique.

As to how the voice moves up, teachers would disagree how to accomplish this. We all agree it is an issue of improving registration through the development process and learning how to move through that pesky passaggio. At that middle point lies the "deep, dark secret" of singing. How the work gets done varies from one teacher to another. I spend a lot of time in vocalizing. Other teachers teach more through music.