The Origin and Development of Musical Scales [pp. 324-343]

THE ORIGIN AND DEVELOPMENT OF MUSICAL SCALES. 329
Ming of the Phrygian and Lydian to be fixed upon other grounds.
The octave, however, soon crept into all systems, altho without supplanting the traditional tetrachords. Thus, the famous
Greek modes were originally octave scales constructed out of
two tetrachordsplus a Pythagorean "tone." The Dorian mode,
for instance, consisted of two Dorian tetrachords cemented together by a "tone":
- -, -, _
In later times these modes underwent considerable extension
and modification, the nature of which changes is quite obscure
and not necessary for us to discuss. How the Greek modes
gradually merged in our modern scales is a subject to which we
shall revert presently.
We have thus rapidly touched upon certain features in
these various melodic systems, not only to emphasize the statement with which we began-that many different scales are now
in use, and that our own are the products of a gradual development-but also to throw some light upon a few facts to which
Helmholtz attaches particular significance.
Before passing on, however, to describe the theory of the
choice of notes in forming a scale, we must pause a moment to
consider the more fundamental problem, Why do we use any
scales whatever?
The songs of all nations proclaim it a universal feeling that
melodies, instead of performing their evolutions freely and continuously, must leap like acrobats from round to round of a
Tonleiter, or scale. Yet it is obvious that in the nature of song
there is no physical necessity compelling this disjointed progress;
for not only can continuous melodies be produced upon the
violin and monochord and any given progressive curve perfectly
imitated upon them, but in the soughing of the wind and often
in the songs of birds, in the cries of animals and in the inflections of human speech, melodic motion unmistakably asserts its
independence of points of support or rest. Why, then, does
music appear always fettered and constrained?
In attempting to answer this question it has been urged that
a careful selection of suitable tones must be had before any
harmonic structure can be reared, since harmony involves pre