- Thomas J. Mathiesen
(fl 4th century ce). Greek writer on music. His Introduction to Music (Eisagōgē mousikē) contains the most complete tabulation of ancient Greek musical notation. He is mentioned by Cassiodorus (Institutiones, ii.5) in the list of important Greek musical authors together with Ptolemy and Euclid (i.e. Cleonides). Alypius’s treatise may have been known to Boethius, who included notational symbols for the Lydian tonos in all three genera (De institutione musica, iv.3–4), but they are not attributed to him and could have been derived from other sources. Nothing is known of his life. The principal reasons for assigning such a late floruit have to do with the name (which is not otherwise attested before the 4th century), the content of the opening prose section (see below), and the general lack of interest in musical notation shown by writers securely dated before the 3rd century ce...