 The makeup of the continuo group is often left to the discretion of the performers (or, for a large performance, the conductor), and practice varied enormously within the Baroque period.At least one instrument capable of playing chords must be included, such as a piano, harpsichord, organ, lute, theorbo, guitar, regal, or harp.In addition, any number of instruments that play in the bass register may be included, such as cello, double bass, bass viol, or bassoon.