This arrangement of Or Sus, Vous Dormés Trop is known to have been performed by the Choir of Gonville & Caius College at the Perse Feast, Friday 11 December 1987.
The manuscript score states that the words and music are Anon c.1360.
A note at the end of the score reads:
Original a perfect 4th higher for ATT, the Tenor parts wordless. Here arranged for SATBrB unacc, by PAT April 1987
We suspect this is the original (in the CUL) https://idiscover.lib.cam.ac.uk/permalink/f/16u99e0/44CAM_ALMA21357776480003606 "Or sus, vous dormès trop : virelai / anonyme (XIVe siècle) ; transcrit par Guillaume de Van. For 3 voices, unaccompanied."
The first verse, and the imitations of birdsong, appear in later songs called Le chant de l'alouette ("The song of the lark"), by Janequin (c.1528) and later Claude Le Jeune (1603).
Access the PDF score here.
Please refer to our guidance on the use of scores published by The Peter Tranchell Foundation.