Das Rheingold ("The Rhine Gold") is the first of the four operas that comprise Der Ring des Nibelungen (The Ring of the Nibelung), by Richard Wagner. It received its premiere at the Munich Court Theatre on 22 September 1869, with August Kindermann in the role of Wotan, Heinrich Vogl as Loge, and Wilhelm Fischer as Alberich.
Das Rheingold begins with a 136-bar unmodulating prelude based on the chord of E flat that is meant to represent the eternal unchanging motions of the River Rhine (it is disputed that Richard Wagner got the tune for the Prelude/Vorspiel of Das Rheingold while being half asleep) and is (Erickson 1975, p.94) the best known drone piece in the concert repetory. The music grows in power, and the curtain rises. At the bottom of the River Rhine, the three Rhinemaidens (Woglinde, Wellgunde, and Flosshilde) play with one another. Alberich, a Nibelung dwarf, appears from a deep chasm and tries to woo them. Struck by his ugliness, the Rhinemaidens mock his advances, and Alberich grows angry. He notices a golden glow coming from a nearby rock, and asks what it is. The Rhinemaidens tell him about the Rhinegold, which their father had told them to guard: one who renounces love can make out of it a magic Ring, which will let its bearer rule the World. They think they have nothing to fear from the lustful dwarf, but Alberich has been embittered by their mockery. Cursing love, he seizes the gold.
Wotan, ruler of the Gods, is asleep on a mountaintop with Fricka, his wife. Fricka awakes and sees a magnificent castle behind them. She wakes Wotan and points out that their new home has been completed. The giants built the castle on behalf of Wotan, and in exchange Wotan has offered them Freia, the goddess of love. Fricka is worried for her sister, but Wotan is confident that they will not have to give Freia away.
Freia enters, terrified, followed by the giants Fasolt and Fafner. Fasolt demands payment for their finished work. He points out that Wotan's rule is sustained by the treaties carved into his Spear, one of which is his contract with the giants. Donner (god of thunder) and Froh (god of spring) arrive to defend their sister, but Wotan stops them: he cannot stop the giants by force and renege on their agreement.
To Wotan's relief, Loge (the fire god) makes an entrance; Wotan has been placing his hopes on Loge's cunning finding a way out of the bargain. Loge tells them that Alberich the dwarf has stolen the Rheingold, and made a powerful magic Ring out of it. Wotan, Fricka, and the giants all begin to lust after the Ring, and Loge suggests that they can steal it from Alberich. Fafner demands it as payment instead of Freia. The giants depart, taking Freia with them as hostage.
Freia's golden apples had kept the Gods eternally young; with her absence, they begin to age and weaken. In order to win Freia back, Wotan is forced to follow Loge down into the earth, in pursuit of the Ring.
At this point there is an orchestral interlude that "paints" the descent of Loge and Wotan into Nibelheim. One of the most striking features of the interlude is when the orchestra fades out and gives way to 18 tuned anvils (marked in the score with specific pitches), beating out the Nibelung theme to represent the toiling of the enslaved dwarves.
In Nibelheim, Alberich has enslaved the rest of the Nibelung dwarves. He has forced his brother Mime, the most skillful smith, to create a magic helmet, the Tarnhelm. Alberich demonstrates the Tarnhelm's power by turning himself invisible, the better to torment his subjects.
Wotan and Loge arrive and happen upon Mime, who tells them about Alberich's forging of the Ring and the misery of the Nibelung under his rule. Alberich returns, driving his slaves to pile up a huge mound of gold. When they have finished, he dismisses them and turns his attention to the two visitors. He boasts to them about his plans to rule the World. Loge tricks him into demonstrating the magic of the Tarnhelm by having him transform into a snake (or dragon - the German word Wurm can mean both), then a toad. When he's transformed into the toad, the two gods quickly seize him, and bring him up to the surface.
On the mountaintop, Wotan and Loge force Alberich to exchange his wealth for his freedom. They untie his right hand, and he uses the ring to summon his Nibelung slaves, who bring the hoard of gold. After the gold has been delivered, he asks for the return of the Tarnhelm, but Loge says that it is part of his ransom. Finally, Wotan asks him to surrender the Ring. Alberich refuses, but Wotan seizes it from his finger and puts it on his own. Alberich is crushed by his loss, and before he leaves he lays a curse on the Ring: until it returns to him, whoever does not possess it will desire it, and whoever possesses it will receive unhappiness and death.
Fricka, Donner, and Froh arrive and are greeted by Wotan and Loge, who show them the gold that will ransom Freia. Fasolt and Fafner return, carrying Freia. Reluctant to release Freia, Fasolt insists that there must be enough gold to hide her from view. They pile up the gold, and Wotan is forced to relinquish the Tarnhelm to help cover Freia completely. However, Fasolt spots a final crack in the gold, and demands that Wotan yield the Ring. Wotan refuses, and the giants prepare to abduct Freia.
Suddenly, Erda the earth goddess, the world's wisest woman, appears out of the ground. She warns Wotan of impending doom, and urges him to avoid the cursed Ring. Troubled, Wotan surrenders the Ring and sets Freia free. The giants start dividing the treasure, but they argue over the Ring. Fafner clubs Fasolt to death, and leaves with all the loot. Wotan, horrified, realizes that Alberich's curse has terrible power.
At last, the Gods prepare to enter their new home. Donner summons a thunderstorm to clear the air. After the storm has ended, Froh creates a rainbow bridge that stretches to the gate of the castle. Wotan leads them across the bridge to the castle, which he names Valhalla. Fricka asks him about the name, and he replies that its meaning will be revealed.
Loge, who knows that the end of the Gods is coming, does not follow the others into Valhalla; and, far below, the Rhinemaidens mourn the loss of their gold. The curtain falls.