Pérotin, Viderunt Omnes
The Gothic style of architecture pioneered by the Basilica of St. Denis (completed in 1144) sparked a wave of new construction across Europe. The Cathedral of Notre Dame de Paris was under construction from 1163 to about 1240. But it wasn’t just new construction and the new Gothic style of architecture on display there. Liturgical music was undergoing dramatic change as well.
Polyphonic (multi-voiced) music was not new at this time. Early forms of polyphony, known as organum, had been introduced at least as early as the 9th century. Early organum added a second voice to the monophonic Gregorian chant melody. In the early forms, the second voice was improvised. But musical styles always become more complex (until the style collapses and is replaced by a new, simpler style). Organum became more elaborate with more ornate melodies and the addition of more voices. Greater complexity created the need for composer control—a plan for coordinating multiple musical events occurring simultaneously. That required more sophisticated notation. And it required the introduction of meter. Gregorian chant was unmetered; it followed the natural rhythm of the text. But multiple voices, all singing different notes and sometimes different texts, needed to stay together. (This paragraph summarizes about five units of our Early Sacred Music course.)
Which brings us to the School of Notre Dame in the late 12th century. Here for the first time we know the names of the composers of individual works: Léonin and Pérotin. And we find prevalent, particularly with Pérotin, the use of “rhythmic modes.” A rhythmic mode is much like poetic meter. A particular arrangement of long and short beats is established and used throughout the piece. It gives the music a distinct rhythmic drive.
The Gregorian chant remains in the long sustained notes of the tenor (tenare = to hold). The bottom voice, the tenor, barely moves while the three upper voices sing similar intertwining parts in rhythm.
Imagine the aural effect of hearing this in the cavernous nave of Notre Dame.