The art of making music by running a bow against a saw arose in several countries around the world when steel saws became widely available some 300 years ago. In the United States it originated in the Appalachian Mountains and reached a peak in popularity in the vaudeville acts of the 1920s and 1930s but faded towards the second world war. However, the art still endures on today maintained alive by many performers.
The sound produced by a musical saw occurs as a result of the friction exerted by the bow upon the saw which causes the steel surface to vibrate, much in the same way as the string of a guitar vibrates when plucked. These vibrations produce compression waves in the surrounding air which are transmitted to our ears and are perceived as sound.
In a guitar, the pitch of the vibrating string can be adjusted by reducing its effective length, which guitarists do by pressing their fingers to the string. In the musical saw, something similar happens when the performer bends and twists the surface of the saw. This creates bounds that restrict the vibrations and changes their pitch in relation to where the bow is applied. The mathematics of the sounds produced by musical saws is quite complex.
In the video below, former university professor turned street performer, Robert (The Saw Man) Maddox, plays Somewhere My Love (Lara’s theme from the movie Dr. Zhivago) in downtown Knoxville, Tennessee.