Sanctus Alexander respondit

Source: 
Aachen (Aix-la-Chapelle), Domarchiv, G 20
Folio: 
271v
Sequence: 
6
Feast: 
Septem Fratrum
Office/Mass: 
L
Genre: 
A
Position: 
5
Cantus ID: 
206396
Mode: 
1
Differentia: 
D3a
Differentia database: 
1--h-h-g-f-gh-gfd--4 70c
Extra: 
058v
Indexing notes: 
The differentia appears to be "fa-g-f-d".