NY AND INTERVALS

178. The _four elements_ commonly attributed to music (in the order of
their development) are: Rhythm, Melody, Harmony, and Timbre (or
tone-color).

179. _Rhythm_ is the regular recurrence of accent. In music it is more
specifically the regular recurrence of groups of accented and
non-accented beats (or pulses)--according to some specified
measure-system. Since rhythm implies continuity, there must usually be
at least two such measure groups in order to make musical rhythm
possible. (See p. 44, Sec. 97.)

180. A _melody_ is a succession of single tones of various pitches so
arranged that the effect of the whole will be unified, coherent, and
pleasing to the ear.

The soprano part of hymn-tunes and other simple harmonized
compositions is often referred to as "the melody."

181. _Harmony_ is the science of chord construction and combination.

The term _harmony_ refers to tones sounding simultaneously,
_i.e._, to _chords_, as differentiated from tones sounding
consecutively, as in melody. The word _harmony_ may therefore
be applied to any group of tones of different pitches sounded
as a chord, although specifically we usually refer to a
_succession_ of such chords when we speak of "harmony." It is
possible to use the same combination of tones in either melody
or harmony; in fact these two elements as applied to modern
music have developed together and the style of present-day
melody is directly based upon the development that has
recently taken place in harmonic construction.

_Harmony_ (as contrasted with _counterpoint_) first began to
be an important factor in music about 1600 A.D., _i.e._, at
the time when opera and oratorio came into existence, when
form was established, and when our modern major and minor
scales were adopted. Before this practically all music was
composed on a contrapuntal basis.

182. _Timbre_ is that peculiar quality of sound which enables one to
distinguish a tone produced by one instrument (or voice) from a tone
produced by an equal number of vibrations on another instrument.

The word _timbre_ is synonymous with the terms _quality of
tone_, and _tone quality_ (Ger.--Klang-farbe), the excuse for
using it being that it expresses adequately in one word an
idea that in our language takes at least two: this excuse
would disappear (and incidentally a mu