Here is a Gregorian hymn we like to sing during Lent:
* * PDF Download • “Audi Benigne Conditor”
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The text is by St. Gregory the Great, who was Pope from 590-604.
And Peter Proctor has sent us this beautiful version by Guillaume Du Fay (1474AD):
* * PDF Download • “Audi Benigne Conditor” (Du Fay)
A version from approximately 1425AD: