Columbia subject headings:
Liturgical drama.
Music--Spain--History and criticism.
Harvard subject headings:
Liturgical drama--Spain--500-1400.
Liturgical drama.
Liturgy and drama--History.
Music--Spain--500-1400--History and criticism.
Music--Spain--History and criticism
Sibyls and music.
Princeton subject headings:
Liturgical drama.
Music--Spain--History and criticism.