​Christopher Perckhover was a Bavarian copyist, who worked mainly on late Renaissance music (Orlando di Lasso, Hans Leo Hassler, Michael Praetorius) at the very begin of the 17th century (so, while most of these composers were still active). 
This Regina Coeli, in one of his collections, is not attributed to anybody, it could as well have been composed by him.
It shows 5 voices, with two "superius" (or superius and cantus) and the cantus firmus (in baritone clef) written on the folium versum; and two other voices (with mezzo and alto clefs) on the rectum.
The German addenda or tropi are also nicely written in red ink: "Christ ist erstanden" ("Christ is risen") and "Freu dich Maria" ("Mary, rejoice").
Transcription by Guido Menestrina 

SCORE INCLUDES:

- FULL SCORE

- SINGLE PARTS FOR 5 VOICES