Let's perform a thought experiment. Imagine carrying out the following pair of instructions:
1) Emit a stream of air through your larynx while opening and closing your vocal cords 440 times per second, resonating the tone most strongly in the range of 800 to 1200 Hz.
2) Play middle C on a piano or pitchpipe. Now sing that note on the vowel [ah].
Obviously, nobody sings according to the procedure outlined in #1 above, although, if you could, it would produce the same result as #2. In reality, we sing by mentally conceiving the sound we want to produce, our bodies responding to the intention of our conscious minds by activating the right muscles at the right time.
This incredibly reliable and accurate mind-body phenomenon works as long as two conditions are met. You must establish and maintain a clear mental concept of the sounds you wish to produce throughout their duration and your muscles must be free to respond in the required manner. (The Alexander Technique helps you to refine both your thinking and your muscle response, which is why it's so beneficial for singers. And other people who need their brains and bodies for what they do.) If you are not yet singing to the best of your abilities, it is either because your mental conception is faulty or vague or inconsistent or because some mental or physical restriction is interfering with the ability of your muscles to respond. In either case, that is what we are working on in your voice lessons.
Do you see that this implies that you are not in lessons to learn how to sing? I don't know how to sing; at least, I have very little idea what is actually physically happening in my body or yours as we make sounds. But I do know that if you have a clear concept of the pitch, volume, vowel, and quality you wish to sing, your body will miraculously coordinate itself to produce your mentally conceived sound, within the limits imposed by the freedom in your muscles. On the other hand, if you try to do something to affect your sound in a particular way, you will more than likely just end up creating tension. We simply can't bring about the intricate coordination for singing by trying to do it.
Today I taught two students who discovered the power of their mind-body connection in singing. Sophie, who recently decided she wanted to explore singing, just had her second-ever lesson today. I had her sing an exercise, which she performed well. Then I wanted her to sing the same pattern at a louder volume (in order to bring in more chest voice participation). First, Sophie tried to "do" the increase in volume, through abdominal pushing. The sound didn't get much louder, but the singer got much tenser! I suggested she just wish for the tone to be louder without doing anything different: this time, she produced a beautiful loud tone with no additional apparent effort. She was able to alternate loud and soft singing at will, just by changing her intention. Her body was responding to her mental conception.
Dan is already a professional singer and an experienced Alexander student besides. In today's lesson, we were focusing on engaging a strong yet gentle, "non-grabby" kind of chest voice, even in notes sung in falsetto. At one point, I asked him to sing a descending arpeggio from high F to the octave below, all on a very bright [ă] vowel (as in "cat"). It started out great, but the quality changed on the lowest note to a more unfocused sound. Dan told me that he observed that he had changed something on that lowest note; in his words, the vowel "dropped back." I encouraged him to repeat the arpeggio, this time maintaining his intention to sing a bright [ă] on every note. With a clear, consistent mental conception, he maintained a consistent tone quality throughout the exercise. He didn't need to try to keep the vowel from dropping back; his mental conception brought about the right conditions automatically.
This mind-body connection is available in all activities, by the way, not just in singing. Most of the problems we have performing tasks of all kinds arise from not having a clear mental conception of what we wish our whole body to do or from factors that interfere with the free response of our muscles. These factors range widely, and include faulty ideas, wrong attitudes, aftereffects of injuries, and habits. An Alexander teacher can help you to discover and eliminate these factors, as well as to practice whole-body thinking.