Are you confused about the so called vocal registers?
When I was a child I already loved to sing. But it seemed to me that I had two voices: the normal voice and then a strange high and funny one which I nevertheless could play with easily. But these two voices didn´t seem to match, and I had to decide which one to use.

Actually, I never dared to try the funny one in public, or on the rare occasions, I performed at school or family events.Nobody could help me because there were no singing teachers in my small hometown.

Much later, to my own surprise even, singing became my profession. I had since learned that indeed, there were two or even more ”voices” – or registers to have fun with while singing. But sometimes the bridging of them – especially going from low to high – was challenging. Not to talk about the weird high range I had discovered. Almost by accident, I noticed that there was a really high extension to my voice. It felt easy! But again, how to learn to transition smoothly over to that stratosphere?

Fast forward years and years. Now I know a LOT about the registers and other technical stuff. Just like me as a young girl, students continue to struggle with their breaks, passaggios and registers. We can read about them in books to find out that even the experts don´t use the same expressions for register terminology which adds to the confusion.
So, here is my contribution in super short form:

The vocal folds (or cords) can vibrate in different ways and it does not only have to do with the pitch. They can even vibrate differently on the same pitch. That´s what can be confusing if you´ve thought that head register is always for high notes or that chest register is only low.

Vocal fold vibration can be either thick or thin. If the folds are thick the sound is usually fairly low and strong. Both men and women sing this way especially in the low range in forte. When we want to sing higher the cords need to become thinner in order to stretch more and create higher pitches, unless we want to shout. Only the edges of the vocal folds then vibrate. But we can use the thin folds vibration also in the lower range to sing softly.

The higher the singer can keep the thickness, the stronger the voice sounds but more breath pressure must also be added. And there is a limit – if you sing too loud and too high with thick folds you can risk damage. A special technique, belting, is needed to do this without vocal injury. Opera singers usually sing with a combination of thin edges of the cords vibration with some thickness and a lot of body strength, depending on the individual physique and how dramatic the role is.

So, in every genre and voice category, singers need to learn to mix the thickness of their vocal folds. The ultimate exercise for this is the messa di voce – starting in pianissimo (=thin folds), then gradually increasing crescendo (=adding vocal fold mass and breath pressure) to a full forte – and then back, controlling the thinning of the cords and balancing the breath pressure and flow. Worth practicing!