Columbia subject headings:
Music--Germany--Rhineland--History--Congresses.
String quartet--Germany--Rhineland--Congresses.
Harvard subject headings:
Music--Germany--Rhineland--History--Congresses.
String quartet--Germany--Rhineland--Congresses.
Princeton subject headings:
Music--Germany--Rhineland--History--Congresses.
String quartet--Germany--Rhineland--Congresses.