The American bass viol, also called a church bass or Yankee bass viol, is a type of bowed string instrument which enjoyed popularity in early 19th century New England for use in aiding Puritan congregational singers. In its time of common use, the instrument was referred to as a bass viol, despite the fact that it more closely resembles a large violoncello than a bass viola da gamba (also known as a bass viol). The size and form of these instruments varies; many are uniquely proportioned folk instruments.