Columbia subject headings:
Musicals--United States--History and criticism.
Opera--United States--History and criticism.
Operetta--United States--History and criticism.
Harvard subject headings:
Musicals--United States--19th century--History and criticism.
Opera--United States--19th century.
Operetta--United States--19th century.
Princeton subject headings:
Opera--United States.
Operetta--United States--History and criticism.
Revues--United States--History and criticism.