Notre Dame School (1150-1300) had three main genres:

• Notre Dame Organum: has rhythmic sections called clausulae; rhythmic sections are in Discant Style
• Conductus became polyphonic, used Discant Style; this uses new tenor, not Gregorian melody
• Motet (beginning 1250): conductus and Notre Dame Organum gave way to the Motet. This is a composition all in Discant Style (rhythmic), has texts in the upper voices as well as tenor
• Cantus Firmus is a melody that is used as basis for a new composition, e.g. Gregorian melodies used as tenors for motets

Ars Antiqua ("Old Art," 1150-1300) coincides with Notre Dame School. During Ars Antiqua, musical developments centered on polyphony. After Ars Antiqua comes

Ars Nova ("New Art," beginning of 14th Century) musical attention turns to Rhythm

• rhythm had always been based on triple subdivisions; now duple and quadruple will be used.
• Most important new genre is Isorhythmic Motet
• defined by the tenor which has recurring patterns of pitch and rhythm
• patterns have different lengths
• Guillaume de Machaut (1304-1377): most important composer of Ars Nova
• wrote lots of isorhythmic motets
• wrote first complete polyphonic setting of Ordinary of Mass: Messe de Notre Dame
• parts were Kyrie, Gloria, Credo, Sanctus/Benedictus, Agnus Dei

Ars Nova in Italy: had different preferences from French composers:

• liked note against note style rather than very long notes in Tenors
• liked duple meters all along
• didn't like using cantus firmi (usually composed new melodies)
• didn't like putting text in every voice
• didn't like isorhythmic motet
• usually put melody in uppermost voice
• most important composer is Francesco Landini (1325-97), originator of Landini Cadence: a melodic formula, not a chord progression