As has been discussed here frequently, we are ever more in an era where functional training is being recognized as “the only way to go”. It’s certainly not new and it certainly does not “belong” to any one teacher or method. It has been around since the 1800s and has been written about by many excellent teacher/authors. Of course, there are also all manner of books full of nonsense perporting to give “real” information when all that is being offered is the latest version of the author’s bellybutton. You do have to know something in order to tell the difference, but, if you are looking to make that determination, it doesn’t take long to discern the genuine from the counterfeit.
We are in a period of time when it is becoming quite fashionable to publish books full of vocal exercises. The exercises of various expert teachers are provided in order to help singers and teachers of singing have specific “things to do” to get a certain desired vocal result. This sounds at first like a good idea but, like everything else, upon further investigation, it may be that this is not always what it seems.
Every functional exercise is only useful in the moment. Even if you know what an exercise typically will prompt as a response in a vocalist’s throat or body, you can never and I mean NEVER be sure that it will do so nor can you be certain that the result you get at first will lead you toward the result you ultimately want. If, indeed, you do not have a broad context in which to apply the exercise and a purpose for it that applies to the situation at hand, you will just be doing what teachers of singing have always done and that is sing the exercise for exercise’s sake. Maybe you are doing this because “someone told you to” or because “it’s supposed to work” because you read about it, but this can be faulty thinking.
A good analogy would be going to the doctor for a check up when you are well. The doctor has a series of standard things she will do and tests she will order to determine the state of your overall health. These might be the same for every patient and work well for most people most of the time. If the doctor is experienced, however, and asks the right questions and is a keen observer, she might spot something that other experts would miss and adjust both her exam and the tests she requests. And, if she typically prescribes a medication for reflux or laryngitis, based on her observations and test results, she might go in a different direction if she determines that the patient needs an adjustment tailored to their particular needs. In other words, the procedures can be standarized but not their application. Nothing can substitute for educated eyes and ears.
So, while I might suggest a general exercise that promotes the development of “head” register (or whatever term you use for higher lighter vocal production) I would only use the exercise in its generic form if this was warranted in the person standing in front of me at any given moment. Since there are infinite ways to vary basic exercises, it might be better if a specific student sang it in a different way. The pitch range, the volume, the musical pattern, the syllables and the vowel all contribute to every exercise. The specific application can only be determined in person, in a session, at the moment you hear the vocalist live (or while you are practicing yourself). Yes, if you know the student’s or your own voice well or if the voice is developed to a certain level, there are times when many different exercises would be fine and when one could easily substitute for another, but you have to know when that would be true and when it wouldn’t work. Not to know is to put both yourself if you are a teacher and the student who is studying with you in a situation where you are potentially wasting time or perhaps even causing problems. You need (a) experience and (b) guidance to know when to do what.
If you sing, don’t be seduced into thinking that people with lots of exercises know what they are for or how to use them for your particular voice and/or vocal situation. Applied incorrectly, functional exercises are no better than the old “think of a big pink mist in the back of your throat” images.