Cleonides

Cleonides was a Greek music theorist, likely active in the second century CE, known for the Introductio Harmonica (Introduction to Harmonics), a concise systematic summary of the harmonic theory of Aristoxenus. The treatise organizes Aristoxenian doctrine into clear divisions covering notes, intervals, genera, scales, modes, and modulation, and is one of our most valuable sources for understanding that school. Almost nothing is known of Cleonides himself; the work was at times wrongly attributed to Euclid or to Pappus. His dates and place are uncertain, and even his authorship rests on manuscript tradition rather than firm evidence.