penetrating on the upper ones (_D_ and _G_).

_Note._ Except in the case of pedal notes, the double bass
rarely plays an independent part, usually moving in octaves
or in unison with the 'cellos, or else doubling the
bassoons. The quality of the double bass tone is therefore
seldom heard by itself and the character of its different
strings is not so noticeable.

The rare ability to connect sounds, or a series of sounds, the
vibration of stopped strings combined with their above-named
qualities--warmth and nobility of tone--renders this group of
instruments far and away the best orchestral medium of melodic
expression. At the same time, that portion of their range situated
beyond the limits of the human voice, e.g. notes on the violin higher
than the extreme top note of the soprano voice, from

[Music: E6]

upwards, and notes on the double bass below the range of the bass
voice, descending from

[Music: D3] (written sound)

lose in expression and warmth of tone. Open strings are clearer and
more powerful but less expressive than stopped strings.

Comparing the range of each stringed instrument with that of the human
voice, we may assign: to the violin, the soprano and contralto voice
plus a much higher range; to the viola, the contralto and tenor voice
plus a much higher register; to the 'cello, the tenor and bass voices
plus a higher register; to the double bass, the bass voice plus a
lower range.

The use of harmonics, the mute, and some special devices in bowing
produce great difference in the resonance and tone quality of all
these instruments.

Harmonics, frequently used today, alter the timbre of a stringed
instrument to a very appreciable extent. Cold and transparent in soft
passages, cold and brilliant in loud ones, and offering but little
chance for expression, they form no fundamental part of orchestral
writing, and are used simply for ornament. Owing to their lack of
resonant power they should be used sparingly, and, when employed,
should never be overpowered by other instruments. As a rule harmonics
are employed on sustained notes, _tremolando_, or here and there for
brilliant effects; they are rarely used in extremely simple melodies.
Owing to a certain tonal affinity with the flute they may be said to
form a kind of link between string and wood-wind instruments.

Another radical change is effected by the use of mutes. When muted,
the clear, singing tone of the s