This edition is based on the Choral Public Domain Library edition by Brian Russell (CPDL #16135), which I checked against two sources, the first of which is a modern edition, and the second is the earliest known manuscript, housed in the Austrian National Library. Apart from halving on note lengths, only two changes have been made from the manuscript source: the b natural in the tenor part in bar 25, which is needed to follow the rules of musica ficta and the last two words of the cantus part have been repeated: although they are not explicitly written out, a repeat is indicated, and this seems the most sensible interpretation. Not

1. di Lasso, Orlando. "Sibylla Samia," in Prophetiae Sibyllarum, edited by Reinhold Schlötterer (Kassel, Germany: Bärenreiter, 1990).
2. Vienna, Österreichische Nationalbibliothek, Musiksammlung, Mus. Hs. 18.744