The headword verb xia/zein, usually derived from the letter chi in the two meanings 'make a cross, use the rhetorical figure chiasmus', could also be derived from the island of Chios (chi 316) in the meaning 'play (music) in the Chian style', just as sifnia/zein (sigma 510) could mean 'play in the Siphnian style'. This observation is the import of this entry; it also occurs at Pollux, Onomasticon 4.65. The two sources attribute the origin of the Chian musical style to the musician Democritus of Chios (RE 5.140, a contemporary of the philosopher of the same name), and that of the Siphnian style to an otherwise unknown citizen of that island named Theoxenides (but Philoxenides or Hypertonides in Pollux).
The Suda entry names as its source the music theorist Praxidamas (RE 22.1751 'Praxidamas 2'), the subject of a lost work by Aristoxenus. It also adds that these two musicians were the first to set their own (musical or poetic?) compositions e)pi\ xrw/matos 'to color' (chi 538). This was apparently a feature, not well understood, of the 'new music' (beta 488, delta 1650, phi 761) and 'new' dithyramb (kappa 2647) beginning towards the end of the 5th. Century B.C. and lampooned by Aristophanes and other comic poets of the time (delta 1029). See note 2 below.
The enigmatic reference to Aristophanes has aroused much debate and led to countless emendations. It may possibly contain an unknown line from Clouds and is for this reason regularly edited and amended in collections of his fragments, most recently in the Kassel-Austin edition (PCG vol. 3.2, fr. 930, with copious notes in Latin and textual variants), but under Dubia. See note 4 below.
[1] The precise meaning of the verb ta/ssw here is open to question (see LSJ s.v., III: web address 1), probably for the arrangement of words to music but perhaps for the adaptation of songs already written to a different type of music.
[2] West (see Bibliography) makes a useful distinction between modern chromatism (196ff.), the insertion of exharmonic semitones and other intervals as colors extraneous to the key or scale in which a piece is written, and the chromatic scale introduced to Greek music during the 5th. century B.C. and quickly the scale of choice for the "new music" of the "new dithyramb" (West 162-71 with notes 1,12-14,19, 246ff.). It is far from clear which is intended here (as is also true in the entry on chroma, chi 538) and I have given both translations. See West's index for other discussions, and Hagel for a somewhat different view. Both the chromatic scale and the use of exharmonic colors were regarded as effeminate and unfit for the education of boys in manliness (West 165 note 14, 246ff.). They were introduced into the choral music of tragedy only in the time of Agathon and Euripides (West 351 note 111, 354, using Psellus, de Tragoedia). Hence the jokes about effeminacy in Clouds and elsewhere in comedy.
[3] This is an error for 'Socrates, Against Eidotheus', a work dubiously attributed to that historian (FGrH 310 F16; RE 5A.804-10 'Socrates 3: Grammatiker'). The work was apparently on music and is probably quoted here, although the punctuation in front of the two uses of w(s is uncertain.
[4] It is uncertain in which clause the word u(potei/nei should be read. In the Suda it comes after a colon and governs the infinitive in its sense 'he offers to' (LSJ II, web address 2). As a result the participle in the genitive case before the colon katatetagme/nou 'of an established…' has been deprived of its syntactic structure. Kassel and Austin, following others, take the two words together, the verb governing the genitive in the sense of tuning strings "under and away from" the established scale or melody. (The genitive is found in this sense after u(faire/w 'take something away from under', LSJ s.v. II 1-3, web address 3.) They place the colon after the verb and transform the following words into a citation from Clouds 969.
The whole entry makes more sense, however, as two quotations, one from Praxidamas, the other from the treatise on music Against Eidotheus attributed to Socrates. The latter must have cited in some context the debate in Aristophanes' Clouds (961ff.) between the Better Argument and the Worse on musical education. The Suda entry has only two sentences (but needs the correction of a misplaced de\):
Praxidamas (says that) "Democritus of Chios and Theoxenides of Siphnos were the first to arrange their personal composition (?poetry) with exharmonic colors."
As Socrates (says) in Against Eidotheus: "As in Aristophanes, one of them undermines established (harmony) after revealing that he is an altar-wit by playing the Chian or the Siphnian in harmonies."
See note 7 below on the untranslatable sexual innuendoes in the passage from Socrates.
[5] See beta 486, beta 487, beta 488, beta 489, beta 490.
[6] The lexicographers agree that the verb 'to play the Siphnian' (sigma 510) is a synonym of skimali/zw 'raise the middle finger' and refers to an act of anal intercourse associated with the Siphnians of antiquity or to the derisive gesture still in use today. The crude jest is not in Clouds. It may be an invention of Socrates attacking Eidotheus and his friends for effeminacy in their musical education. It was probably based on knowledge that there was no Siphnian school of music. In the passage it is introduced by sexual innuendo in the phrase katatetagme/nou u(potei/nei (LSJ s.v. ta/ssw III , web address 1, with the prefix kata- 'down upon').
[7] Harmony (alpha 3977) originally meant the stringing and fine-tuning of musical instruments to a predetermined system. From the first sections of Aristoxenus, Harmonics [OCD(4) pp.163-4], it is clear that the first writers recognized as harmony only the enharmonic genus in its various modes, e.g. Dorian, Phrygian. Thus the description of the chromatic genus as a twisting of harmony.