The instrument that uses a bow to produce sound is the violin. This string instrument, which is played by drawing a bow across its strings, has a rich, resonant sound and is a staple in orchestras and various music genres. The violin typically has four strings tuned in perfect fifths and can express a wide range of emotions due to its dynamic tonal capabilities. It's an essential instrument in classical, folk, and contemporary music. The technique of bowing creates vibrations in the strings, causing the air around the instrument to resonate, producing its distinctive sound.