Columbia subject headings:
Harvard subject headings:
Organ (Musical instrument)--Italy--History--18th century--Congresses.
Organ (Musical instrument)--Italy--Registration--Congresses.
Organ music--Italy--History and criticism--Congresses.
Organists--Italy--Biography--Congresses.
Princeton subject headings:
Organ builders--Italy.
Organ music--Italy--19th century--History and criticism.
Organists--Italy.