Perotins

Perotins refers to a group of composers active in Paris during the late 12th and early 13th centuries, associated with the Notre Dame school of polyphony. While their individual identities are not always clearly distinguished, the most prominent figure is Léonin, often considered the founder of the school. Pérotin, believed to be his successor, is credited with significant innovations in musical composition, particularly in the development of organum.

Organum, a form of early polyphony, involves adding one or more melodic lines to an existing plainchant. Perotins' contributions included the introduction of duplum (two voices), triplum (three voices), and quadruplum (four voices), moving beyond the simpler forms of earlier periods. His use of rhythmic modes, a system for organizing musical rhythm, was also a crucial development, allowing for more complex and structured polyphony.

The music of the Notre Dame school, including the works attributed to Perotins, was primarily intended for liturgical use within the cathedral. Surviving manuscripts, such as the Magnus Liber Organi, contain examples of their compositions. The style is characterized by sustained, slow-moving bass lines (tenor) derived from chant, with more melismatic and rhythmically active upper voices. The music of Perotins represents a pivotal moment in the evolution of Western music, laying the groundwork for much of what would follow in the development of harmony and polyphony.