Aristoxenus

Aristoxenus of Tarentum was a Greek philosopher and music theorist of the 4th century BCE, a pupil of Aristotle in the Peripatetic school. He is best known for his 'Elements of Harmonics,' the most important surviving ancient treatise on music theory, in which he treated harmony through the trained ear rather than purely through numerical ratios. He also wrote on rhythm and produced biographies of philosophers, now largely lost.