How did isorhythm organize music in the 14th century?

In 14th-century French polyphony, isorhythm served as a primary structural principle used to organize musical compositions. It functioned by systematically applying a repeating rhythmic pattern, known as the talea, across a given segment of a piece, often extending this pattern throughout the entire composition.12

This rhythmic organization was frequently paired with a color, which refers to a repeating melodic sequence. While the color and talea might not always coincide in length, their simultaneous application provided a rigorous framework for integrating the different voice parts of a work.12

Isorhythm was most prominently utilized in the 14th-century motet, allowing composers to achieve structural depth and complexity without relying on the fixed rhythmic modes of the 13th century. This technique was a hallmark of the Ars Nova period, with Guillaume de Machaut standing out as one of its most significant masters. By providing a method to unify separate melodic layers, isorhythm remained a popular and influential device in European music for over a century.12