Didymus, Chalcenterus (of the Brazen Guts)
Didymus, Chalcenterus (of the Brazen Guts)
Didymus, Chalcenterus (Of the Brazen Guts), Greek scholar and grammarian of Alexandria who flourished from c.80 to 10 B.C. He earned the nickname of Chalcenterus for his large output of books, which is said to have numbered about 3,500 vols. He wrote a tract on music, now known only by an epitome of Porphyry’s, and some quotations by Ptolemy. In his system the octave of the diatonic genus is formed by 2 precisely similar tetrachords, and in all 3 species of tetrachord (diatonic, chromatic, enharmonic) the ratio for the interval of the major third is 4:5. He also recognized the difference between the major and minor whole tone; this difference (9/8:10/9 = 81:80) is, therefore, rightly termed the “comma of Didymus.” Salinas and Doni have written on his musical system.
—Nicolas Slonimsky/Laura Kuhn/Dennis McIntire