Columbia subject headings:
Music--20th century--History and criticism.
Music--Philosophy and aesthetics.
Music--Social aspects--History--20th century.
Nineteen sixties.
Harvard subject headings:
Avant-garde (Music)--History--20th century.
Music--20th century--History and criticism
Music--20th century--Philosophy and aesthetics
Music--Social aspects--History--20th century.
Nineteen sixties
Princeton subject headings: