or basso continuo
In Baroque music, a special subgroup of an instrumental ensemble.
It consists of two instruments reading the same part: a bass instrument, such as a cello or bassoon , and a chordal instrument, most often a harpsichord but sometimes an organ or lute . Its appearance in the early 17th century reflected the radically new musical texture of accompanied melody that was especially typical of the new vocal genre of opera . The continuo (which has a counterpart in the bass and rhythm guitar of a rock band) came to be employed in virtually all ensemble music of the Baroque era.