A Comfortable Pitch
It is to be assumed that the student will, in these experiments, take the pitch in his voice which is most comfortable. Having mastered the combination tone on "Ah" at any pitch, it will be easy to try other pitches and other vowels. "Ah" is the natural vowel, but having secured the "know how" through a correct production of "Ah" the same results may be attained with any other vowel produced in a similar way. "E" as in see has of course more of the strident quality, the high, bright quality and "OO" as in moon more of the dark, but even these extreme tones may be so placed that they become enriched through the employment of resonance of all those parts of the mouth, nose and body which may be brought naturally to reinforce them.
"Ping"
I have never met a singer who was not looking for "ping" or what is called brightness. Most voices are hopelessly dead, and therefore lack sweetness. The voices are filled with night—black hollow gloomy night or else they are as strident as the caterwauling of a Tom Cat. The happy mean between the extremes is the area in which the singer's greatest results are attained.
Think of your tone, always. The breath will then take care of itself. If the tone has a tremulo, or sounds stuffy or sounds weak, you have not apportioned the right amount of breath to it, but you are not going to gain this information by thinking of the breath but by thinking of the tone.