Das Rheingold is the first opera in Wagner's Ring Cycle.
Here is the official trailer for the opera.
What stands out most in the video is the 40 tonne machine that consists of 24 aluminium and fibreglass planks which pivot like see-saws around a central beam. The planks can be moved into many positions for the different scenes in the performance.
The magic begins before a word is sung, as the orchestral prelude conjures up the beginnings of the world at the bottom of the Rhine. The planks, stretched flat on the stage floor, begin to undulate gently, mimicking the music. Suddenly, the planks rise up to reveal the three Rhinemaidens swimming upward in harness, exhaling bubbles as they sing. (Source of quotation.)
Another stunning effect is in the scene when Wotan and Loge descend to the realm of the Nibelheim. The planks become an Escher like bridge, which body doubles of the singers traverse with the assistance of ropes.
The set planks can also be arranged in more variable shapes, as shown in the scene below were the the gods debate the ultimatum given by the giants who stand on raised planks in the background. Note another theatrical effect as Loge the god of fire is surrounded by a nimbus of flame.
In the video below the director Robert LePage explains his philosophy of the staging of opera. As a Wagnerian novice I particularly applaud his awareness of the variety of operatic audiences. He is aware that opera companies have an educational role (for people like me).
Not everyone supports his approach, and some of the reviews were unfavourable. For examples of unfavourable reviews see here, here and particularly here.
For more positive reviews see here, here and here .
For what it is worth, I really enjoyed the staging and the music of this performance.
Here is a summary of the plot of the opera, taken from this source :
The story begins in the depths of the Rhine river, where the three Rhinemaidens (think "mermaids") are playing in a state of primal state-of-nature innocence. Enter Alberich the Nibelung (dwarf) from a fissure beneath the earth, who spies the three and lusts after them. The Rhinemaidens taunt him and humiliate him for his ugliness and awkwardness. In his rage at being rejected, Alberich steals the Rhinegold from them, having learned that he who is willing to renounce love will thereby gain the ability to forge a ring of power from the gold. The maidens had assumed that no one in his right mind would make such a renunciation, but Alberich is enraged and wants revenge. He disappears with the gold, leaving the bereft maidens to sing a song of loss and grief that will reappear all through the four operas. Alberich forges the ring and makes himself lord over all the Nibelungen.
Meanwhile, Wotan wants a grand castle for the gods to live in as a testament to his greatness. He has contracted with the two giants Fasolt and Fafner to build him the castle. On the advice of the wily Loge, god of fire, Wotan has promised the Giants Freia, goddess of youth and beauty, in return for the building; Loge has assured Wotan that he will find him a way out of the deal. Fasolt and Fafner, having finished the castle, come for their payment. Wotan is stuck; since all his power rests on the treaties inscribed into his spear, he cannot renege on the deal, and the giants make off with the terrified Freia.
Loge, having learned of Alberich's ring, suggests to Wotan that they steal it from Alberich and offer it to the giants as a substitute payment. Wotan agrees, though he secretly plans to keep the ring for himself. The two go down into the earth to Nibelheim where the dwarves live. There Alberich has enslaved the dwarves and forced them to mine him an enormous pile of gold. Wotan and Loge succeed in kidnapping Alberich and take him back to the gods' abode on the mountain top. There they relieve Alberich of the hoard and of the ring. Alberich is as shattered by the loss of his ring as Gollum ever thought of being. He places on the ring a terrible curse, bringing endless misery to all who possess or seek it.
Wotan and Loge offer the giants Alberich's hoard of gold in return for Freia. Fafner accepts, though Fasolt has by now become rather sweet on Freia and wants to keep her. The hoard is piled up, but Fafner wants one last thing: Alberich's ring, now on Wotan's finger. Wotan refuses, the giants threaten to call off the deal and leave with Freia, and in the middle of the hubbub there appears out of the ground Erda ("earth"), goddess of the earth and the world's wisest woman. She warns Wotan to flee the ring's curse, foretells that a death-laden day is coming for the gods, and disappears. Wotan relents and gives the ring to the giants, who immediately fall to arguing about the division of the spoils. Fafner kills Fasolt on the spot, and goes off with the loot.
The problem resolved for the time being, Wotan and the rest of the gods prepare to enter into the new castle, which Wotan dubs "Walhall"--literally, the "hall of the fallen heroes." Fricka, his wife, asks him the meaning of the name, and Wotan says, "If what I'm planning works out, its meaning will become clear to you." The gods enter Valhalla, as the Rhinemaidens sing a mournful song of loss.