Metaphysics is the branch of philosophy which deals with the nature of existence or being. It involves speculative and abstract reasoning about matters which are not amenable to scientific explanation.
Methaphysical, therefore, is the adjective that describes reasoning of this type; it may also incorporate a sense of the visionary and the supernatural.
Richard Wagner (1813-1883) was a highly influential German composer and conductor. He is particularly well-known and admired for his thirteen operas which include The Flying Dutchman (Der fliegende Holländer), Tannhäuser, Lohengrin, Tristan and Isolde, The Mastersingers of Nuremberg (Die Meistersinger von Nürnberg), and the 4-opera cycle known as The Ring of the Nibelung (Der Ring des Nibelungen).
Listen here to the 'Sailors Chorus' from Wagner's The Flying Dutchman on Spotify.
Listen here to the 'Bridal Chorus' from Wagner's Lohengrin on Spotify.