The Anonymus Bellermanni is a collection of material on music, by one or more unknown authors, transmitted in a number of Byzantine manuscripts and first published by Johann Friedrich Bellermann [de] in 1841.
Martin West comments: "It is drawn to a marked extent from Aristoxenus and Aristides Quintilianus but contains some valuable matter not found elsewhere, including half a dozen little instrumental tunes and exercises.
"[1] Along with four poems attributed to Mesomedes, and not counting various fragments on papyrus, it is one of the only examples where a piece of ancient Greek music has survived in the manuscript tradition.
[3] Among other things, the document explains the symbols used in music for notes which are extended to two, three, four, and five time-units (disemes, trisemes, tetrasemes, and pentasemes).
[4] Other symbols mentioned in the treatise are the symbol for a musical rest (shaped Λ), and the stigmai or dots above the note-symbols, which apparently indicate the arsis of the foot.