Perotin's works are preserved in the Magnus Liber, the "Great Book" of early polyphonic church music, which was in the collection of the cathedral of Notre Dame in Paris. The Magnus Liber also contains the works of his slightly earlier contemporary Léonin. However, attempts by scholars to place Perotin at Notre Dame have been inconclusive, and very little is known of his life. His music, and that of Léonin, have been grouped together as the "School of Notre Dame."
Perotin composed organum, the earliest type of polyphonic music that went beyond the monody of Gregorian and other types of chant. He pioneered the styles of organum triplum and organum quadruplum (three- and four-part polyphony); in fact his Sederunt principes and Viderunt omnes are among only a few organa quadrupla known. He was one of very few composers of his day to sign his name to any of the music he wrote.
A prominant feature of his compositional style was to take a simple, well-known melody and strech it out in time, so each syllable was hundreds of seconds long, and then use each of those held notes (the tenor, Latin for "holder", or cantus firmus) as the basis for complex rhythmic harmonies above it. The result was that one vocal part sang a complex, quickly moving line (a "discant") over the chant below, which was extended to become a slowly shifting drone.
His music influenced modern "minimalist" composers such as Steve Reich, indeed, it can be argued that Perotin himself was a proto-minimalist. His works include Viderunt omnes, Sederunt principes, Alleluia posui adiutorum, and Alleluia natiuitas in the organum style as well as Dum sigillum and Beata uiscera in the single-melody conductus style. (The conductus sets a rhymed Latin poem called a sequence to a repeated melody, much like a contemporary hymn.) Later in life he earned the title "Perotin Magister" which means Perotin the master or expert.