Until the last half of the
twentieth century, vibrato as a form of
expression in music was largely taken for granted. All forms of
legato and
sustained playing on any
string instrument in the
orchestra is subject to the enriching qualities of vibrato.
A proper vibrato is acheived by the
shaking back and forth of the wrist and elbow without picking up the finger that is
depressing the string in a proper position. This is done by a performer to increase the
warmth and
tone color of a given passage; as such, when a
composer marks the
score senza espress it is generally taken to mean 'without vibrato.' It lessens the chance for a performer to add expression or any interpretation.
Igor Stravinsky was proud and fond of using this.
Vibrato is such a widely used
practice that actually seeing the word in the
score is indicative of a place where the string player should
grossly over-exaggerate the vibrato used, either to increase drama and
tension or to parody. The generally accepted practice of using vibrato in most or all expressive, sustained, or non-
stacatto passages leads to the combined vibrati of an entire string section, and this is what gives the section its tonal color, its
character, and its ability to inspire
emotion in the modern listener.