Perotin was one of the great composers of the late twelfth and early thirteenth centuries.
He is believed to have worked in Paris, France at the Notre Dame Cathedral and studied under the
great Notre Dame Organum composer Leonin. Theorists such as Anonymous IV
disagree with this opinion. Anonymous IV notes that Perotin edited Leonin's Magnus liber
organi (The Great Book of Organum) adding much improved clausulae and puncta (forms of
discant), however they suggest that Perotin was not a student of Leonin. Perotin composed in
styles such as organum, conductus, and discanT. He is known for expanding organum duplum
(two
voice organum) to organum triplum and quadruplum (three and four voice organum). Only a
handful of four voiced organa were composed during Perotin's time, and one of the greatest
organum quadruplums of this time is Perotin's Sederunt. Perotin's works not only include his
original compositions but his revisions of Leonin's Magnus liber organi as well. His revisions of
the Magnus liber include abbreviating the content and adding improved discant. Perotin was
considered the greatest composer of discant of his time.
In the eleventh and twelfth centuries the six rhythmic modes were developed and being used
in composition. These rhythmic modes each denote their own rhythmic pattern: mode 1)
long-short; 2) short-long; 3) long-short-medium; 4) short-long-medium; 5) long-long; and 6)
short-short-short. These modes were often interchanged within a composition to provide
rhythmic
variety. There are three styles of Notre Dame Organum, each differing in its use of
measured or unmeasured rhythm: organum purum, where both voices have unmeasured rhythms;
copula, where the upper voice or organalis has a measured rhythm while the vox pricipalis is
unmeasured; and discant, where both the upper and lower voiced have measured rhythms. Often
the tenor, lower melodic line taken from plainchant, carries a repeated rhythmic pattern
throughout the discant.
During the time of Perotin florid organa was often replaced with discant clausulae, and old
clausula were replaced with substitute clausula, which contain new rhythmic motives. Before
Perotin the upper voices of a multi-voiced organum were composed individually with respect to
the tenor line. Composers paid little attention to the overall texture of their music. Perotin
treated polyphony differently and paid close attention to the texture of all voices when composing.
His innovation lead him to such things as exchanging phrases between voices, substituting
clausula, and using contrasting rhythmic modes. These new composition techniques eventually
lead composers to add new texts, usually in French or Latin, to old organum compositions to
form the Motet. This genre flourished from after Perotin career well into the nineteenth
century.
Web links to Perotin and Notre Dame Organum: