The new musical genre of florid organum emerged from the Notre Dame School. In florid organum singers decorate Gregorian chant melodies with figuration above them in an effort to take church music into higher realms of spiritual experience. Most of the names of the creators of Notre Dame polyphony are unknown today.

ars antiqua

The composers of the Notre-Dame school are all anonymous except for two, Léonin (q.v.), or Leoninus (late 12th century), and Pérotin (q.v.), or Perotinus (flourished c. 1200), both of whom are mentioned in a 13th-century treatise by an anonymous Englishman studying in Paris.

1151

Léonin (active ca. 1165-1185), or Leoninus, of the Cathedral of Notre Dame in Paris, is the earliest known composer of polyphonic art music and the creator of controlled rhythm and meter, as well as of the earliest notation to convey rhythm. About the life of Léonin absolutely nothing is known.

1201

Léonin, Latin Leoninus, (flourished 12th century), leading liturgical composer of his generation, associated with the Notre Dame, or Parisian, school of composition.

organum

Léonin

Organum was originally improvised; while one singer performed a notated melody (the vox principalis), another singer—singing “by ear”—provided the unnotated second melody (the vox organalis). Over time, composers began to write added parts that were not just simple transpositions, thus creating true polyphony.

• Sacred music. The mass. Motets. Anthems. Cantata and oratorio.
• Occasional music.
• Secular music.
• Madrigals and related forms. Development of the madrigal. The Italian madrigal. Cultivation of the dialogue. The French chanson and English madrigal.