One of the striking points of difference between the old and the modern method is seen here: In the old system both student and instructor listened to the sound of the voice from the very first lesson. The aim was always to sing a pure tone. Under the present system attention is directed in the early stages of instruction to the way in which the tones are formed, not to how they sound. Thus faults of production can be gradually and almost imperceptibly acquired; by the time the attempt is made to correct them, they have already become a habit.
Taylor, David Clark. “New Light on the Old Italian Method: An Outline of the Historical System of Voice Culture, with a Plea for Its Revival.” (1916).