Singing is a physical skill. The exercises that singing teachers give students are meant to provoke change in the muscular systems that produce voiced sound.
An exercise is a stimulus and the sound the singer makes is the response. If the response is not good, it could mean that the stimulus was incorrect, vague, confusing or not possible. If the person giving the instruction has no idea what the exercise is meant to do, the exercise is just a random shot in the dark. Great way to learn to sing or to change how your singing happens.
That’s like learning to bowl by knowing that you need the ball to do something in the alley with the pins but not knowing what, exactly, that is or how it is supposed to be accomplished. Should it just “come to you” that the ball needs to be flung hard with one hand to roll down the alley so that it hits the pins and they all fall down at once? If it did not just occur to you would that make you an untalented bowler?
All explanations about singing that are NOT functional can only be musical or dramatic. The mental images that are poetic can stimulate various kinds of sound, but they can’t help someone learn to change the core ingredients of their own sound. They relegate the singer to being stuck with the sound they already make, albeit in a more deliberate or controlled manner. They might make the singer more imaginative, more expressive or even more audible, but they will not really help change anything from the inside out in terms of vocal or breathing patterning.
If the singer’s response did not seem to be good and the stimulus was, there has to be something else going on in the first immediate result. The most common possibility is that the singer is getting the right response but that it is too small to register, either as movement of the vocal organs or in the externally perceived sound. Repetition of the same stimulus will eventually produce a new audible and kinesthetic result. If the person understood what was being asked and the teacher understood what was being asked and those two things agree, the singer will get there in due time. If, however, the teacher does not understand what is being asked, or the student misunderstands the teacher or both (very common occurance), then how can the result be anything but random? Vocal development done randomly is better than none at all, but it is a very slow, very frustrating way to learn.
The teacher has to think in a certain manner in order for any program of vocal training to be effective. The teacher must listen to the singer for function, first. That means the teacher understands what normal vocal function is and is not. That means that the teacher also understands developmentally what extended, professional music vocal behavior is, not just for classical styles but for all styles, and what various vocal ranges and voice types do in normal people under typical circumstances. It means that the teacher understands individual variance that is still normal and normal consistency that is not limitation. It means that the teacher can assess what is going on that is good and should be kept and maintained, what is missing and needs to be cultivated and what is wrong with the singer’s vocal production and how to fix all of that using exercises. It means that the teacher also knows how to adjust the exercise so that it is more applicable, easier to do, and that it is done effectively but at whatever level the singer can manage.
It means that the teacher sees and hears progress quickly (and progress always means change and improvement in some area). It means that the student agrees that things are improving (if it is only the teacher, that problem has to be addressed). It means that the singer’s instrument is getting ever closer to a freer, easier more satisfying vocal production that is suitable to that particular person’s professional or personal goals and that both parties agree that this is so.
You do the exercise until it produces the desired result first time, every time. Then you ask the student to go repeat it on his or her own, allowing the exercise to do its job. When that takes place, you no longer need that exercise. You do it until you don’t have to do it any more because it has done it’s job.