"But not," Mr. Pilzer continued, "not as it is too often mistakenly
employed. Of course, any trained player will draw his bow across the
strings in a smooth, even way, but that is not enough. There must be an
inner, emotional instinct, an electric spark within the player himself
that sets the _vibrato_ current in motion. It is an inner, psychic
vibration which should be reflected by the intense, rapid vibration in
the fingers of the left hand on the strings in order to give fluent
expression to emotion. The _vibrato_ can not be used, naturally, on the
open strings, but otherwise it represents the true means for securing
warmth of expression. Of course, some decry the _vibrato_--but the
reason is often because the _vibrato_ is too slow. One need only listen
to Ysaye, Elman, Kreisler: artists such as these employ the quick,
intense _vibrato_ with ideal effect. An exaggerated _vibrato_ is as bad
as what I call 'the sentimental slide,' a common fault, which many
violinists cultivate under the impression that they are playing
expressively.