Columbia subject headings:
Marx, Karl, 1818-1883--Influence.
Music--Philosophy and aesthetics.
Wagner, Richard, 1813-1883--Criticism and interpretation.
Wagner, Richard, 1813-1883. Ring des Nibelungen.
Harvard subject headings:
Marx, Karl, 1818-1883--Influence.
Music--Philosophy and aesthetics
Wagner, Richard, 1813-1883--Criticism and interpretation.
Wagner, Richard, 1813-1883. Ring des Nibelungen.
Princeton subject headings:
Marx, Karl, 1818-1883--Influence.
Music--Philosophy and aesthetics.
Wagner, Richard, 1813-1883--Criticism and interpretation.
Wagner, Richard, 1813-1883. Ring des Nibelungen.