Columbia subject headings:
Gregorian chants.
Instrumental ensembles.
Motets.
Music--Spain--500-1400.
Harvard subject headings:
Gregorian chants.
Instrumental ensembles.
Motets.
Music--Spain--500-1400.
Princeton subject headings:
Gregorian chants.
Motets--500-1400.
Music--Spain--500-1400.