Marchetto da Padova

Marchetto da Padova (Marchettus of Padua; fl. 1305 – 1319) was an Italian music theorist and composer of the late medieval era. His innovations in notation of time-values were fundamental to the music of the Italian ars nova, as was his work on defining the modes and refining tuning. In addition, he was the first music theorist to discuss chromaticism.

Read more about this composer on Wikipedia.