-c. 1155-1225 (13th century)
-Latin Perotinus
-Léonin's student, rival and successor
-Paris, Notre Dame School
-Revised the Magnus Liber Organi by adding a 3rd and 4th vocal part (chant, duplum, triplum, and quadruplum), with shorter phrases, clearer rhythms, and more frequent use of the Ionian 'major' mode
-composed substitute clausulae to replace organum originally composed by Leonin
-wrote in the Ars Antiqua style
-Latin Perotinus
-Léonin's student, rival and successor
-Paris, Notre Dame School
-Revised the Magnus Liber Organi by adding a 3rd and 4th vocal part (chant, duplum, triplum, and quadruplum), with shorter phrases, clearer rhythms, and more frequent use of the Ionian 'major' mode
-composed substitute clausulae to replace organum originally composed by Leonin
-wrote in the Ars Antiqua style