Frederick W. Root
The title comes from an article written by Frederick W. Root, who, among other things, interviewed Manuel García, taught in Chicago, and was a highly influential vocal pedagogue during his lifetime.
Written at the end of Root's life (he did not live long enough to read the proof before publication), his words are relevant for voice teachers today even though they were written ninety-four years ago, and this is because he dives into the divide between empiricism and science. It's a matter that is still with us. You still read articles where science types decry the use of metaphorical language (they call it flowery language) while the empiricists note that no spectral graph (ie voce vista) can tell the viewer if the tone is beautiful or not. In short: articles like Root's reveal singing teachers are still dealing with the same issues as a hundred years ago.
What has changed over the years? Information. There is a dizzying amount of information available as regards the anatomy, physiology and acoustics of the voice. Does it help the singer? Probably not. But it could help the teacher be a better teacher. That only happens - in my view- if the teacher in question is a trained listener. One doesn't, however, become a trained listener by learning facts. Instead, one becomes a great listener by listening to the nature of vowels and what they enable the singer to do. This is what the Old Italian School empiricists concerned themselves with. They had a non-verbal language of sound that was passed from teacher to student.
In addition to the presented article, an excellent dissertation on Root's teaching by David Christopher Grogan can be read here. Of particular interest to this writer is Chapter 5 which deals with the three root vowels, [i], [a] and [u], which I have written about in previous posts. My observation? These vowels -when sung purely - enable the singer to master any language. That said: you have to have your wits about you to accomplish this. Your ear has to be open!