The art of the actor cannot be separated from the body, the instrument through which the art is expressed. Thus the ability to express the full gamut of human emotional responses is dependent on the mastery of the instrument of expression. This mastery is, however, not achieved through manipulation of the instrument, as one might manipulate a musical instrument to produce sound. Unlike a musical instrument, the body is a living organism, that operates under the laws of Nature, which must be understood and cooperated with, rather than manipulated. Only in this way is it possible to express truthful emotional responses to an audience.
Applying the Alexander Technique to the art of acting primes the body (including the voice and mind) for the task of expressing these emotions. It does this not by imposing predetermined physical or emotional states on the body and mind, but by removing them, thus removing the obstacles to the free embodiment and expression of a plethora of potential emotional responses.
For the singer the primary instrument of the expression is the voice, which is housed in the body, and is in fact, integral with the body, and as such, is the body. We tend to think of the voice in terms of the vocal cords, or the diaphragm, or soft palate, or other parts that directly influence the production of sound, but this view is too fragmented, and fails to recognise that the functioning of the voice cannot be separated from any part of the body.
The application of the Alexander Technique to the art of singing is to see that it is the whole organism that sings, and that for full and free production of sound and emotional expression we need to consider the whole being in the act of singing.
While the singer needs full mastery of the vocal mechanism, and the actor needs a mastery of the vocal and physical instrument for non-musical expression, the dancer is called on to express emotion entirely through the body, without the use of the vocal mechanism. Thus the range and repertoire of physical movement, and the mastery thereof for the expression of emotion, constitutes the art of the dancer.
As for the singer and actor, it is imperative for the dancer that a non-manipulative cooperation with the body is achieved for it to be able to perform the dynamic and precise tasks being required of it. The natural design and tendencies of the body must be clearly understood so that freedom of movement and expression can be attained.