Notre-Dame School
The 12th- and 13th-century Parisian composers who built the first large-scale polyphony around Gregorian chant.
What it sounds like
The Notre-Dame School refers to a group of composers active at the cathedral of Notre-Dame in Paris between roughly 1160 and 1250, whose central practice was organum: a Gregorian chant melody stretched into very long held notes (the tenor) over which one, two or three upper voices moved in faster ornamental lines. Two figures dominate the record — Leoninus (active c. 1150-1175), credited with the 'Magnus Liber Organi,' and Perotinus (active c. 1180-1205), who expanded organum to three and four voices in 'Viderunt omnes' and 'Sederunt principes.' The music was sung in the cathedral and is inseparable from its long stone reverberation.
How it came about
Construction of the new Gothic cathedral began in 1163, and the rise of the University of Paris in the same period made the city a center for liturgical and theoretical innovation. Notation reached a turning point with the development of rhythmic modes that made coordinated polyphony writable for the first time. The repertoire was carried by manuscript across western Europe, and the theorist Anonymous IV (writing in the 1280s) is the main source for the names of Leoninus and Perotinus.
What to listen for
Listen for the contrast between the tenor voice, holding a single syllable of chant for what can feel like a minute, and the upper voices weaving above. The harmonies favor open fifths and octaves and avoid the sweet thirds that came later. The acoustics matter: the music was composed for a building with eight or more seconds of reverb.
If you only hear one thing
Perotinus's four-voice 'Viderunt omnes' (c. 1198) is the natural entry — a Christmas gradual sustained over enormous slow tenor pitches. Follow with 'Sederunt principes' (c. 1199) for the larger work, and Leoninus's two-voice settings for the earlier layer.
Trivia
Nothing definite is known about Leoninus or Perotinus as individuals — the names come from a 13th-century English theorist who refers to 'magister Leoninus' and 'magister Perotinus' as authorities. The Hilliard Ensemble and the Ensemble Organum each made influential modern recordings in the 1980s that returned this repertoire to wide circulation.