I have recently become interested in reading, and even playing, from early manuscripts such as the St. Emmeram Mensural Codex.
The St. Emmeram Mensural Codex is a hand-written manuscript of polyphonic settings, with sacred texts, dating back to the mid 15th century. A special feature of the codex is that it exhibits two forms of mensural notation. In some sections the copyist(s) used the earlier, solid form (black notes with red coloration) of mensural notation; other sections used the later, white form (white or void note heads with black coloration). I plan to provide select modern editions here. A facsimile of the manuscript, is published by Dr. Ludwig Reichert Verlag: Wiesbaden and available from sellers such as OMI
The St. Emmeram Mensural Codex is currently housed in the Bayerischen Staatsbibliothek München (Clm 14274). It is not the same as the much earlier Codex Aureus of St. Emmeram, a 9th century illuminated gospel book, also housed in the same library (Clm 14000). Both the mensural codex, and the Codex Aureus have been housed in the former St. Emmeram's Abbey.
Scores edited by John M O'Donnell include select modern editions from: