Ista est*

Source: 
Worcester, Cathedral - Music Library, F.160 (olim 1247) (with hymnal)
Folio: 
270r
Sequence: 
25
Feast: 
Catharinae
Office/Mass: 
V2
Genre: 
A
Position: 
M
Cantus ID: 
202663
Mode: 
*
Addendum: 
P: 410