Didymos
Encyclopedia
Didymos was an ancient Greek music theorist in the last century before Christ. He was a predecessor of Ptolemy at the library at Alexandria.
as measured string lengths from which the following proportions can be calculated:
Like Archytas
he used a major smell, but appears to have been the first to use it in the diatonic as sum of the large and small whole tones as for the proportions (10:9)•(9:8)=5:4 obtains.The difference of these whole tones is the so-called syntonic comma, also referred to as Didymos' comma
Theory
We know of his theory only indirectly from the works of Porphyry and Ptolemy. There one finds examples of his tetrachordsTetrachord
Traditionally, a tetrachord is a series of three intervals filling in the interval of a perfect fourth, a 4:3 frequency proportion. In modern usage a tetrachord is any four-note segment of a scale or tone row. The term tetrachord derives from ancient Greek music theory...
as measured string lengths from which the following proportions can be calculated:
- diatonic Tetrachord: (16:15)(10:9)(9:8)
- chromatic Tetrachord: (16:15)(25:24)(6:5)
- enharmonic Tetrachord:(32:31)(31:30)(5:4)
Like Archytas
Archytas
Archytas was an Ancient Greek philosopher, mathematician, astronomer, statesman, and strategist. He was a scientist of the Pythagorean school and famous for being the reputed founder of mathematical mechanics, as well as a good friend of Plato....
he used a major smell, but appears to have been the first to use it in the diatonic as sum of the large and small whole tones as for the proportions (10:9)•(9:8)=5:4 obtains.The difference of these whole tones is the so-called syntonic comma, also referred to as Didymos' comma