Substitute clausula

A clausula is a passage (or several passages) composed as a replacement for a segment of Notre-Dame organum. It employs a short excerpt of plainsong or plainchant (e.g. Gregorian chanting) in the tenor voice and new material in the organal voice(s). Such clausulas often employed rhythmic modes (using copula or discant). Since the tenor usually came from a melismatic portion of the plainsong, the clausula seemingly had no text (or only one or two syllables). The clausula could be plugged back into the original organum setting, but evidently may also have had an independent musical existence. The clausula was the immediate forerunner of the early motet.<br>