ell-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. The _measure_ is a
group of beats,--two, three, four, or more, at the option of the
composer. The bounds of the measures are visibly represented (on the
written or printed page) by vertical lines, called bars; and are
rendered orally recognizable (to the hearer who does not see the page)
by a more or less delicate emphasis, imparted--by some means or
other--to the _first_ pulse or beat of each measure, as accent, simply
to mark where each new group begins. Those who play or sing can
imagine how vague, and even chaotic, a page of music would look if
these vertical bars were omitted; and how much more difficult it would
be to read than when these (not only accustomed, but truly necessary)
landmarks are present. Precisely the same unintelligible impression
must be, and is, conveyed to the hearer when _his_ landmarks, the
accents, are not indicated with sufficient emphasis or clearness to
render him sensible of the beginning of each new measure.

* * * * * *

The same primary system of measurement and association which is
employed in enlarging the beats to measures, is then applied to the
association of the measures themselves in the next larger units of
musical structure, the Motive, Phrase, Period, and so forth. Unlike
the measures, which are defined by the accents at their _beginning_,
these larger factors of form are defined chiefly at their _end_, by the
impression of occasional periodic interruption, exactly analogous to
the pauses at the end of poetic lines, or at the commas, semicolons and
the like, in a prose paragraph. These interruptions of the musical
current, called Cadences, are generally so well defined that even the
more superficial listener is made aware of a division of the musical
pattern into its sections and parts, each one of which closes as
recognizably (though not as irrevocably) as the very last sentence of
the piece.

Cadences serve the same purpose in music, then, as do the punctuation
marks in rhetoric; and an idea of the senselessness and conf