Didymus the Musician

Didymus the Musician (Greek: Template:Math) was a music theorist in Rome of the end of the 1st century BC or beginning of the 1st century AD, who combined elements of earlier theoretical approaches with an appreciation of the aspect of performance. Formerly assumed to be identical with the Alexandrian grammarian and lexicographer Didymus Chalcenterus, because Ptolemy and Porphyry referred to him as Didymus ho mousikos (the musician), classical scholars now believe that this Didymus was a younger grammarian and musician working in Rome at the time of Emperor Nero.Template:Sfnp He was a predecessor of Ptolemy at the library of Alexandria. According to Andrew Barker,Template:Sfnp his intention was to revive and produce contemporary performances of the music of Greek antiquity. The syntonic comma of Template:Math is sometimes called the comma of Didymus after him.Template:Sfnp

Among his works was On the Difference between the Aristoxenians and the Pythagoreans (Template:Math Template:Math Template:Math Template:Math Template:Math).

Theory

We know of his theory only indirectly from the works of Porphyry and Ptolemy. There, one finds examples of his tetrachords as measured string lengths from which the following frequency ratios are calculated:

tetrachord type	interval 1st–2nd	interval 2nd–3rd	interval 3rd–4th
diatonic	Template:Big	Template:Big	Template:Big
chromatic	Template:Big	Template:Big	Template:Big
enharmonic	Template:Big	Template:Big	Template:Big

Like Archytas, he used a major third, but appears to have been the first to use it in the diatonic as the product of the major (9:8) and minor (10:9) whole tones, as the proportions produced by Template:Nobr The ratio of these whole tones Template:Nobr is the so-called syntonic comma, also referred to as Didymos' comma.Template:Sfnp Template:Sfnp