 ‘Harmonics’ is the Ancient Greek discipline that studied musical entities, from intervals to scalar systems (Barker 1990: 3). The Pythagorean tradition marked the start of an influential approach to harmonics, focused on the definition of musical entities in mathematical terms. Early contributors to this approach were Philolaus of Croton (c. 470–c. 385 BCE) and especially Archytas of Tarentum, a contemporary of Plato (Huffman 1993, 2005).