Bowed instruments are a family of string instruments that produce sound by drawing a bow across their strings. Common examples include the violin, viola, cello, and double bass. These instruments are typically made of wood and have a hollow body that amplifies the sound. The pitch is altered by changing the length of the vibrating string, which can be done by pressing the strings against the fingerboard. The bow itself is made of horsehair stretched between the ends of a wooden stick. When the bow is drawn across the strings, it causes them to vibrate, creating sound. Bowed instruments are widely used in various music genres, including classical, folk, and contemporary music.