Columbia subject headings:
Gluck, Christoph Willibald, Ritter von, 1714-1787--Criticism and interpretation--Congresses.
Opera--Europe--18th century--Congresses.
Harvard subject headings:
Gluck, Christoph Willibald, Ritter von, 1714-1787--Criticism and interpretation--Congresses.
Opera--Europe--18th century--Congresses.
Princeton subject headings:
Gluck, Christoph Willibald, Ritter von, 1714-1787--Criticism and interpretation--Congresses.
Opera--Europe--18th century--Congresses.