, another of the name, was an eminent musician of Alexandria, and, according to Suidas, cotemporary in the first century with the emperor Nero, by whom he was much honoured and esteemed. This proves him to have been younger than Aristoxenus, and more ancient than Ptolemy, though some have imagined him to have preceded Aristoxenus. He wrote upon grammar and medicine, as well as music; but his works are all lost, and every thing we know at present of his barmonical doctrines is from Ptolemy, who, by disputing, preserved them. However, this author confesses him to have been well versed in the canon and harmonic divisions; and if we may judge from the testimony, even of his antagonist, he must have been not only an able theorist in music, but a man of considerable learning. As this musician preceded Ptolemy, and was the first who introduced the minor tone into the scale, and, consequently, the practical major 3d -f, which harmonized the whole system, and pointed out the road to counterpoint; an honour that most critics have bestowed on Ptolemy, he seems to have a better title to the invention of modern harmony, or music in parts, than Guido, who appears to have adhered, both in theory and practice, to the old division of the scale into major tones and limmas. “The best species of diapason,” says Doni, “and that which is the most replete with fine harmony, and chiefly in use at present, was invented by Didymus. His method was this: after the major semitone E F T-f, he placed the minor tone in the ratio of V, between F G, and afterwards the major tone between G A; but Ptolemy, for the sake of innovation, placed the major tone where Didymus placed the minor.Ptolemy, however, in speaking of Didymus and his arrangement, objects to it as contrary to the judgment of the ear, which requires the major tone below the minor. The ear certainly determines so with us, and it is therefore probable, that in Ptolemy’s time the major key was gaining ground. Upon the whole, however, it appears that these authors only differ in the order, not the quality of intervals. 2


Burney’s Hist, of Music, vol. I. Hawkins’s Ditto.