An intabulation of the Sanctus from Josquin: Missa Faysan Regretz. This mass appears to have been popular in Spain. It was first published in Missarum Josquin Liber Tertius (Fossombrone: Petrucci, 1514).
The indication in the rubric: “y no se mudan las claves” implies that the intabulation is ciphered for a vihuela in G as the the previous pieces. The mode could be either 1 or 2. It has been listed here as mode 2 on the basis of the superius range.
Bloxham2000 provides some excellent insight into the Mass and it being derived from a chanson by Walter Frye. Narváez’s intabulation is discussed by Bevilacqua.