Columbia subject headings:
Hasse, Johann Adolf, 1699-1783--Congresses.
Harvard subject headings:
Hasse, Johann Adolf, 1699-1783--Congresses.
Princeton subject headings:
Church music--18th century--History and criticism--Congresses.
Europe--Intellectual life--18th century.
Hasse, Johann Adolf, 1699-1783--Congresses.
Opera--18th century--History and criticism--Congresses.