Vibrato: when to use it, when to stop

Continuous vibrato is the easiest tell that a player has not been trained at a professional level. Real masters use vibrato as one expressive choice among many, including no vibrato. They modulate speed and width depending on the style. Most students, by contrast, vibrate the moment a note is held longer than an eighth note, regardless of style. This is a habit that has to be unlearned before serious audition prep.