Over the past thirty years of my experience as a teacher, I have watched the vocal education community grow into a better understanding of the physicality of the voice. There is a need to recognize the voice as a physical thing and the importance of learning about it and working on it, much like an athlete trains to hone their ability. As a vocalist, the sport that we practice is the mastery of our body and the stamina to avoid injury while producing a vocal sound free of tension. The incredible growth of technology (CAT scans, MRIs, etc.) have given us the scientific proof behind vocal pedagogy and technique.
Your voice is your body, and if you treat it properly it will always work for you. As our bodies and muscles begin to wear with age, we must be vigilant, wise, and realistic in our use of them. Since the voice is nothing more than a collection of muscles, cartilage, and bones, it is just as influenced by age as is any other part of our body. We must work at maintaining the voice, just like an athlete.
I believe it is my job as a teacher to look at each student as a unique individual, with unique qualities and a unique history that requires me, as the teacher, to work at finding how best to help that individual. Not all students work in the same way.
There is more than one way to teach vocal production successfully, however if it involves anything that can't be proven by science, it is hoohaa. Not to say that the performance aspect doesn't involve emotion, imagination, and more than a bit of magic, however the production of the sound needs to be based on a solid, physical technique. To know what is working, how it's working, why it's working or is not working is essential. Once the technique is in place, the magic can begin as we layer our performance over it.
A wobble? No problem. Air control? Easy to master/regain mastery. Looking to increase or solidify your range? Always more to do and ways to grow. Rethinking your instrument? How can that do anything other than make it stronger? Being a good vocalist is like being a scientist, questioning and doubting and examining and studying only serve to solidify what we do!