Some string players are cellists, lutists, and violists. Cellists play the cello, a stringed instrument of the violin family, with four strings tuned in perfect fifths. Lutists play the lute, a plucked string instrument with a neck and a deep round back. Violists play the viola, a stringed instrument similar to the violin but slightly larger and with a deeper sound. All three instruments are used in classical music, as well as in folk and popular music.