Early Polyphony, continued

Trend is to more independence of voices

• Free Organum: documented in Micrologus (11th Century, ³short account²) by Guido d¹Arrezzo, a medieval monk and music theorist.
• begins with monophonic Gregorian chant, then a trope is added, and an organal voice is added to the trope. Organalis can be sustained against principalis; can move in parallel, oblique or contrary motion, even crossing voices.
• Melismatic organum (1100-1150). In 12th century, voices switch places: Gregorian melody is lower, very long, sustained notes; now called Tenor. Upper line is now called Duplum (³second voice²), much faster
• Notre Dame School (1150-1300): includes rhythmic sections alternating with non-rhythmic sections of melismatic organum. Rhythmic sections are in Discant Style; a section in Discant Style is a clausula.
• Composers: Leonin and Perotin are traditionally recognized as the two main composers of Notre Dame school; some doubt as to their existance.
• Leonin supposedly lived 3rd quarter of 12th century, wrote Magnus liber organi (Big Book of Organum), organal setting of certain portions of Mass for entire liturgical year.
• Perotin was supposedly Leonin¹s successor (late 12th, early 13th century); his style included lots of clausulae and extra voices. Extra voices were called Triplum and Quadruplum as applicable. 3-part writing became standard in 13th century
• Polyphony was extended beyond strict liturgical music: Conductus became polyphonic, using discant style. Tenor was newly composed, not a Greg. melody (parallels tradition of monophonic conductus)
• By mid-13th century polyphonic conductus gave way to Motet. Motet is all in discant style, used Gregorian tenors; biggest difference is that now upper voices have text. Duplum is now called Motetus ; other voices continued as triplum, quadruplum. Example is MM # 10