A string ensemble is a group of musicians who play string instruments, such as violins, violas, cellos, and double basses. The most common type of string ensemble is a TRIO, which consists of three musicians playing the same type of instrument or different types of instruments. A string TRIO typically includes a violin, a viola, and a cello. This type of ensemble is often used in classical music, but can also be found in other genres such as jazz and folk music.