Columbia subject headings:
Opera--19th century.
Ritual in opera.
Harvard subject headings:
Opera--19th century--History and criticism.
Opera--Europe--19th century--History and criticism.
Opera--Italy--19th century--History and criticism.
Ritual in opera.
Princeton subject headings:
Melodrama.
Opera--Italy--19th century.
Verdi, Giuseppe, 1813-1901.