Aristides Quintilianus in Wikipedia
Aristides Quintilianus (Greek: Ἀριστείδης Κοϊντιλιανός) was the Greek author of an ancient musical treatise, Perě musikęs (Περί Μουσικῆς, i.e. On Music), who probably lived in the third century AD. According to Marcus Meibomius, in whose collection (Antiq. Musicae Auc. Septem, 52) this work is printed, it contains everything on music that is to be found in antiquity (except for Aristoxenus). (See Pauly-Wissowa, Realencyc. ii. 894.)
This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed (1911). Encyclopćdia Britannica (Eleventh ed.). Cambridge University Press.