Baccheius or Baccheius Senior（*Bakxei/os), surnamed Senior (ὁ γέρων). We know nothing of his history. Fabricius (Bibl. Graec. ii. p. 260, &c.) gives a list of persons of the same name, and conjectures that he may have been the Baccheius mentioned by M. Aurelius Antoninus (de Rebus suis, 1.6) as his first instructor.
εἰσαγωγή τέχνης μουσικῆς. The treatise consists of brief and clear explanations of the principal subjects belonging to Harmonlics and Rhythm. Baccheius reckons seven modes (pp. 12, 18), corresponding to the seven species of octave anciently called by the same names. Hence Meibomius (praef in Arist. Quint.) supposes that he lived after Ptolemy, who adopts the same system, and before Manuel Bryennius, in whose time an eighth (the Hypermixolydian) had been added. But the former supposition does not seem to rest on satisfactory grounds.