What is the technique called when string players tap on the strings with wooden parts of their bow?

The technique where string players tap on the strings with the wooden part of their bow is known as "col legno." This term translates from Italian to "with the wood," aptly describing the action of using the bow's wood instead of the horsehair to produce sound. When employing col legno, musicians create a percussive effect that can add unique textures to the music.

This technique is particularly effective in certain styles and compositions, as it produces a different tonal quality compared to the traditional bowing methods. It can evoke a range of emotions and atmospheres, making it a valuable tool in a composer’s repertoire. Various composers, especially in contemporary classical music, have utilized col legno to introduce innovative sounds and enhance the overall musical experience.