Many of Wagner's opera's are based on mythology and contain some kind of religious symbolism. This has inspired many authors to give esoteric or occult interpretations of Wagner's works.
The Magical Pantheon Of Wagner's Ring: Qabalistic Initiation through the Ring Cycle of Operas, J. C. Kaelin
Richard Wagner's birth chart.
Richard Wagner - Composer, Music-Dramatist, Author by Michael D. Robbins © 2002.
Wagner's Parsifal by Rolf May
Quote from a lecture by Rudolf Steiner at Hamburg, November 17, 1906 (GA 54)
If you could only observe, as a practicing occultist, the way in which a Wagner opera works on the different members of the human nature, it would convince you that it is especially music which is able to send its vibrations deep into the etheric body.
Mysteries of the Great Operas: Faust - Parsifal - The Ring of the Nibelung - Tannhauser - Lohengrin, Max Heindel
Parsifal and the Secret of the Graal Unveiled by Theodor Reuss
The Chalice Of Ecstasy Being a Magical and Qabalistic Interpretation of the Drama of Parzival, Frater Achad