Vibrato is the oscillation between two points of a pitch. The top point is what we hear as the pitch. Essentially, vibrato is the flattening of the pitch and returning to it.
There are two main variables to keep track of: width and speed. There is also a minor variable: pressure. We’ll start with focusing on width and speed.
Without the bow and in harmonic position, slowly slide your finger along the string from the nut to the end of the neck. Be sure to keep your finger balanced. Gradually slide faster, add pressure, and shorten the distance that you slide until you feel your finger heating up from the friction. Then immediately settle on a note and play with the bow.
Center your finger over a note. Pull your finger back so that the note is noticeably flat and then back up to the correct pitch. Feel the skin of your finger move instead of rotating your hand. Practice this first in a steady rhythm with the quarter note to 60 beats per minute. Then practice this exercise at full speed. Practice varying the width and speed of your vibrato. Flatten the note more for more width. Flatten it less for a more narrow vibrato.
Put your hand at the base of the neck by the body. Pull your hand back and then hit the instrument with your hand and repeat. Start slowly then increase speed. Change positions as necessary for each finger.
- I have to put my hand as high as 5th position on the A string when doing this exercise with my first finger.