The document summarizes music of the Middle Ages from Gregorian chant to the Renaissance. It describes two periods: Ars Antiqua from 1100-1300 characterized by organum style polyphony adding harmonies to chants; and Ars Nova from 1300-1450 which saw innovations in notation and mass composition. Representative composers of each style like Leonin, Machaut, and Landini advanced musical composition through genres like motets and mass ordinaries. Secular musicians also traveled performing love songs, though most composers remained anonymous church servants.