Most music composed at Notre Dame was attributed to either Leonin or Perotin, but may have been composed by others in their style. A treatise by Anonymous 4 gave credit to Perotin for seven pieces. The polyphony of this period has been preserved in four large thirteenth-century manuscripts.
Impact and Legacy of Notre Dame SchoolEdit
The school "...produced the earliest repertory of polyphonic music to gain international prestige and circulation."
The Notre Dame school of composition introduced four categories that were imitated by many others afterward:
The most notable of these is the motet, a genre that will continue to pop up in different ways throughout Western Art Music. When Perotin added clausulae to Leonin's music, he also wrote in words for the added parts. This became the thirteenth century Parisian motet as we know it, in three parts, often in two or three languages running simultaneously.
Leonin left a great legacy with his Magnus Liber Organi, or great book of organa that had a year's worth of material. His two part polyphony served to segue the course of music from monophonic plainchant to the rich polyphony of the Ars Nova period and beyond.
Other sources include The Encyclopedia Brittanica online: