Instruments in the string family have many things in common including shape, material, and how they make sound. String musicians make sound by vibrating the strings on their instrument with their finger or bow. When a musician pulls the bow across the strings or plucks a string with their finger, the string vibrates and makes a sound. There are four main members of the string family: the violin, the viola, the cello, and the bass. The violin is the smallest and plays the highest while the bass is the largest and plays the lowest.