What musical school of thought did Leonin and Perotin represent?

Leonin and Perotin are key figures of the medieval period known for their contributions to early polyphony, particularly in the realm of sacred music. They were associated with the Notre Dame school of polyphony in the 12th and 13th centuries. Their works exemplify the Ars Antiqua style, which is characterized by the early development of polyphonic writing.

Ars Antiqua translates to "old art" and denotes the period that succeeded plainchant, marking the emergence of multiple independent melodic lines. Leonin is credited with developing the two-part organum style, while Perotin advanced this further by integrating three or four voice parts, creating richer textures. The innovations during this time laid the groundwork for further developments in Western music, contrasting sharply with the styles that would eventually emerge in the Renaissance, Baroque, and Romantic periods.

Thus, the identification of Leonin and Perotin with the Ars Antiqua is accurate, as they were pioneering figures in this foundational era of polyphonic music.