Since there seems to be an interest, I will share some of what I’m getting from learning to sing better.
The first part, aside from posture, is the difference between head voice and chest voice. Both are valuable, depending on the song and the effect we want to have.
Singing is caused by pushing air over the vocal cords. However, there is a lot more to it than that, and most of us don’t even think about it. It goes without saying that breathing is very important. Without a full lungful of air, singing is difficult, putting it mildly. However, what happens next controls whether the singing will be in head voice or chest voice.
High notes are often sung in head voice. In head voice, the music is literally coming from your head. You can actually feel the vibration in your sinuses and it is largely controlled by the mouth and soft palate. For many women, singing in a head voice is natural because the vocal cords are shorter anyway, producing a higher pitch. They may need to teach themselves to use a chest voice.
In a chest voice, the music comes from deeper down, in the chest, the chest and throat have much more play in a chest voice, which tends to be easier for most men. A chest voice often results in a greater volume, not necessarily needing more breath to produce it.
It is important to mention falsetto. A falsetto is similar to a head voice, but it is airier and relatively weak. Many men use a falsetto when singing very high notes, though they might use both head voice and falsetto if they are skilled at it. Skilled female singers also use both.
An excellent example of a woman who used both was Whitney Houston. I’m including a clip here to show how she slips between head voice and falsetto seamlessly. She starts the song in falsetto. Notice how soft her voice is, with an airy quality. When she sings “If I should stay, I’ll only get in the way”, she’s singing falsetto. She stays there until she starts singing “And I will always love you”. Then she switches to head voice so seamlessly that most people aren’t even aware of it. Notice that her voice gains strength at that point. She still isn’t singing with her chest voice, but she uses her head voice to control the strength of her voice.
She again switches, this time to chest voice, when she sings “Bittersweet memories, this is all I’m taking with me”. The transition is so smooth that a listener usually isn’t even aware of it, but the sound is being driven by her chest and not by the resonation of her mouth and sinuses.
Also notice that at this point, her mouth also opens wide, often a sign of chest voice use. This allows her voice out fully, without restriction. This is more important for one of the other points I’ll share, but it is worth noticing. Also notice that when she begins to sing the chorus this time, she is fully in chest voice. The volume and strength both increase. There is a slight expense, though. Whitney sings in a natural head voice, so she needs more air to sing in chest voice. If you watch closely when she starts singing the chorus, she must take a big and rapid breath.
What is impressive is that she continues singing in chest voice until the point where her guy is jumping into the lake, then she transitions for a moment into head voice, before switching back again. This shows an enormous control of chest voice/head voice/falsetto, which Whitney mastered.
It also shows that she practiced over and over. What happens if you don’t practice and try to switch between chest voice and head voice or visa versa? Your voice will often break. You may not even be aware that you are trying to switch from one technique to the other. It is one of the most common causes of a break in the voice. Trying to sing out of range will also cause a break, but people are more apt to realize that they are pushing their vocal range when they do it.
Amazingly, Whitney also manages to sing some very high notes in chest voice. Most people, myself included, couldn’t come close to doing that.
Okay, so how about for a male voice. Here is a Pentatonic clip that shows chest voice, head voice, and falsetto. I’ll let you listen and pick up the various types of voice, but I will mention that Scott Hoying begins the song using a falsetto, though the song is well within his range and he doesn’t need to use a falsetto voice. He does this on purpose, for effect. Pay particular attention to Mitch Grassi, wearing the broad-rimmed hat, because he also masterfully switches between head voice, chest voice, and falsetto. Kristin Maldonado also uses all three.