Columbia subject headings:
Hymns--History and criticism--Congresses.
Secularization (Theology)--Congresses.
Secularization--Congresses.
Harvard subject headings:
Hymns--History and criticism--Congresses.
Secularization (Theology)--Congresses.
Secularization--Congresses.
Princeton subject headings:
Hymns, German--Germany--History and criticism--Congresses.
Sacred vocal music--Germany--Congresses.