Soon after his removal to Zurich, he commenced to compose the libretto of the "Nibelung's Ring." This work was founded on the famous old German poem, "_Die Nibelungen Lied_," but with very important modifications of Wagner's own. It is divided into four works. In the first, "_Das Rheingold_," the gold of the Rhine, is stolen, and a curse is laid upon it. The second opera of the series is "_Die Walkuere_." In this work the remarkable character of Brunhilde is the central figure. She is one of the Wish-maidens of Odin, whose duty it was to conduct the souls of slain heroes to Walhalla, the dwelling place of the gods. The entire conception of this character is unique, and still more unique in the musical way in which it is worked out. We find in this work also the mother and father of Siegfried, and the opera closes when Brunhilde is thrown into the magic slumber with the fire around her. The third opera of the series is that of Siegfried, the half-divine, half-human hero, who knows no fear--who slays the dragon that captures the gold of the Rhine--awakens Brunhilde from her magic sleep, etc. The fourth opera is called "The Twilight of the Gods," or "The Death of Siegfried." I will not consume space by describing this poem in detail, since this material is easily accessible in every encyclopedia. I have already treated it at considerable length in the second volume of my "How to Understand Music." These works are especially remarkable upon a musical side. The opera of the "Rhinegold" is a little monotonous, but the orchestral score contains many points of beauty, and "The Valkyrie" is beautiful throughout, conceived in a very masterly and poetic vein; the instrumentation, also, is extremely noble and beautiful. In the whole of these two works there is scarcely a single piece which can be played apart from the rest as a concert number. The drama moves straight on from one thing to another. There are no melodies of the conventional type, and the music is closely woven together, like the effects of an April day, with storms, sunshine and shadows following each other without any perceptible break. So great has been the advance in musical taste since these were first composed, that "The Ride of the Valkyries," a famous descriptive piece for orchestra, forming the prelude of the second act, has been played in all parts of the world, as also the "Magic Fire Scene," which closes the opera. These are given over and over again by Thomas, and arrangements of them are often played at the piano. Directly he had finished "_Die Walkuere_," Wagner sent it to Liszt, and a letter with it, in which he modestly admitted that he thought it was very fine, or words to that effect. Liszt, on his part, was delighted with it. He wrote a most beautiful and noble letter to Wagner about it, and a little later he speaks of Hans von Buelow having been with him, when he could not refrain from giving him "a sight of Walhalla." So he brought out the