From Byzantine Greek ἴσος (ísos [equal]) [?]; NB¹: According to Wikipedia "Ison is a drone note, or a slow-moving lower vocal part, used in Byzantine (i.e. Eastern Christian) chant and some related musical traditions to accompany the melody, thus enriching the singing"; NB²: In his chapter »Chomonie und historische Phonetik des Altrussischen« (in Vinogradov [➺ sources]), Ch[ristian] Hannick refers to the stopìca (WS: стопица [foot]) as its equivalent in Russian Byzantine music; NB³: "Chomonie" is the method, chiefly practised in 16th and 17th century Russian Orthodox unison diatonic chant, in which long coloraturas were sung (according to the author of the entry in the »Harvard dictionary of music«, without explanation: "in bad taste" [sic]) to meaningless syllables (such as a-ne-na, after which it is called "Аненайки" [Anenàjki]); A similar method, known as "Teretism" (i.e. after the syllables used: te-re-rem) was used for the same purpose in Byzantine chant of the same period; NB⁴: ➺ related terms.