"The bow is the key to this mastery in expression, in interpretation: in
a lesser degree the left hand. The average pupil does not realize this
but believes that mere finger facility is the whole gist of technic. Yet
the richest color, the most delicate _nuance_, is mainly a matter of
bowing. In the left hand, of course, the _vibrato_ gives a certain
amount of color effect, the intense, dramatic tone quality of the rapid
_vibrato_ is comparable on the violin to the _tremulando_ of the singer.
At the same time the _vibrato_ used to excess is quite as bad as an
excessive _tremulando_ in the voice. But control of the bow is the key
to the gates of the great field of declamation, it is the means of
articulation and accent, it gives character, comprising the entire scale
of the emotions. In fact, declamation with the violin bow is very much
like declamation in dramatic art. And the attack of the bow on the
string should be as incisive as the utterance of the first accented
syllable of a spoken word. The bow is emphatically the means of
expression, but only the advanced pupil can develop its finer, more
delicate expressional possibilities.