Fulgebat in venerando duplex

Source: 
Worcester, Cathedral - Music Library, F.160 (olim 1247) (with hymnal)
Folio: 
209v
Sequence: 
18
Feast: 
Gregorii
Office/Mass: 
M
Genre: 
R
Position: 
1.1
Cantus ID: 
006752
Mode: 
1
Addendum: 
P: 287