The term 'Bass Relative' refers to two instruments in the string family: the VIOL (4 letters) and the CELLO (5 letters). The VIOL is a bowed string instrument that is played with a bow, and is the predecessor of the modern-day Violin. It is also known as the Viola da Gamba, and was popular in Europe during the Renaissance and Baroque periods. The CELLO is a larger version of the VIOL, and is held between the knees of the player while being played. It is a popular orchestral instrument, and is used in many genres of music.