The words of a language (also sounds, it is true) have established meanings, so familiar and definite that they recall and re-awaken impressions of thought and action with a vividness but little short of the actual experience.

Tones, on the contrary, are not and cannot be associated with any _definite_ ideas or impressions; they are as impalpable as they are transient, and, taken separately, leave no lasting trace.
Therefore, whatever stability and palpability a musical composition is to acquire, _must be derived from its form, or design_, and not from its totally unsubstantial material.

It must fall back upon the network traced by the disposition of its points and lines upon the musical canvas; for this it is that constitutes its real and palpable contents.
THE EVIDENCES OF FORM IN MUSIC .-- The presence of form in music is manifested, first of all, by the disposition of tones and chords in symmetrical measures, and by the numerous methods of tone arrangement which create and define the element of Rhythm,--the distinction of short and long time-values, and of accented and unaccented (that is, heavy and light) pulses.
This is not what is commonly supposed to constitute form in music, but it is the fundamental condition out of which an orderly system of form may be developed.

As well might the carpenter or architect venture to dispense with scale, compass and square in their constructive labors, as that the composer should neglect beat, measure and rhythm, in his effort to realize a well-developed and intelligible design in the whole, or any part, of his composition.

The beats and measures and phrases are the barley-corn, inch and ell of the musical draughtsman, and without these units of measurement and proportion, neither the vital condition of Symmetry nor the equally important condition of well-regulated Contrast could be clearly established.
The _beat_ is the unit of measurement in music.