Columbia subject headings:
Catholic Church--Hymns.
Church music--Germany.
Gregorian chants--History and criticism.
Hymns, Latin.
Manuscripts, Latin (Medieval and modern)--Facsimiles.
Music--Manuscripts--Facsimiles.
Neumes.
Harvard subject headings:
Catholic Church--Hymns.
Church music--Germany.
Gregorian chants--History and criticism.
Hymns, Latin.
Manuscripts, Latin (Medieval and modern)--Facsimiles.
Music--Manuscripts--Facsimiles.
Neumes.
Princeton subject headings: