Vibrato's a musical effect, produced in singing and on musical instruments by a regular pulsating change of pitch, and's used to add expression and vocal-like qualities to instrumental music. Vibrato can be characterised by the amount of pitch variation ("depth of vibrato") and speed with which the pitch's varied ("speed of vibrato"). Vibrato and tremolo The terms vibrato and tremolo are sometimes used interchangeably or inappropriately, although the strict definitions of each describe them as s… (More on Vibrato)