Rosin Your Bow

Why You Should Rosin Your Bow

by Tim Leung

It is often said that if the violin is the “body”, then the bow is the “soul”. Indeed, while the violin generates the beautiful sound, it is the bow that provides the articulation that turn notes into music. From a physics point of view, this is (roughly) how the sound is generated: as the bow is being pulled, the static friction generated between the hair and the string pulls the string along. As the string is being pulled along, its tension increases, and very soon the friction no longer holds. The string then bounces back and starts vibrating, at the frequency (pitch) that is determined by the length, diameter, tension and the density of the string. At every cycle of the vibration, the string will once again align with the movement of the bow, and the bow will once again pull on the string, allowing the vibrations to continue. The vibration of the string is called “forced damped harmonic motion”. It’s called harmonic because the vibration of the string is cyclic at a single frequency; it’s damped because energy is being dissipated from the string all the time (without the bow, the vibration will eventually stop); and it’s forced because the friction from the bow is also adding energy to the system.

The keyword here is friction. Without it, the bow never makes a sound. And in order to generate sufficient friction, we put rosin on the hair of the bow. Different types of rosin from different makers ave slightly different properties, and a violinist may get a different sound quality.  Typically, rosin should be applied to the bow every couple of hours of playing.

Elite Music Academy is a private music school in Toronto offering music lessons in most instruments and styles. Violin lessons are offered for students of all ages and skill level. For a free consultation please contact the main desk at 416 406 5355 ext1.