5. Tolkien's Ring and Der Ring des Nibelungen
Tolkien did not like Wagner and his interpretations of the German myths. "He delighted his friends with recitations from Beowulf, the Pearl, and Sir Gawain and the Green Knight, and recounted horrific episodes from the Norse Volsungasaga, with a passing jibe at Wagner whose interpretation of the myths he held in contempt"  and "The comparison of his Ring with the Nibelungenlied and Wagner always annoyed Tolkien; he once said 'Both rings were round and there the resemblance ceased.' 
The origin of the Nibelung's Ring was different to start with. It derived from the sacred Rhinegold, kept and preserved by the Rhinemaidens. They have been charged by their father to guard the treasure so that no false thief should carry it from the waters.
They also reveal that if the Rhinegold is worked into a Ring, it will have inestimable power;
Alberich: Is the Gold of value
Woglinde: He would not abuse
Wellgunde: Inheritance of the world
However, there is a price to be paid;
Woglinde: Only he who has
Wellgunde: We are safe indeed
The loathsome Nibelung Alberich, having been taunted by the Rhinemaidens, and having had his advances rejected, elects to take the Rhinegold and to forsake love.
Alberich: If I might win inheritance
He then returns to Nibelheim where he creates the Ring.
The existence of the Ring is revealed to Wotan, chief of the Gods, by Loge. Wotan has to pay the giants Fafner and Fasolt for the construction of Valhalla. The original transaction was that Freia, Goddess of Youth, would be given to them as payment. However, the consideration is renegotiated, and it is agreed that enough gold to cover Freia will be paid instead. This gold must be obtained, and the only place where such an amount exists is Nibelheim. The cunning Loge, who negotiated the original transaction, puts the matter this way;
Loge:....I sought in vain,
Wotan: Of the Rhinegold
Frika: Would the bright ornamentation
Loge: A husband's fidelity
Wotan: Methinks it would be wise
Loge: A magic rune
Donner: The dwarf would make
Alberich has compelled his brother and chief smith Mime to craft a Tarnhelm which will allow the wearer to change into anything he wishes. Alberich harasses Mime, and invokes the power of the Ring;
Loge and Wotan go to the underground world seeking the Ring. They discover from Mime precisely what Alberich has done;
Mime: With wicked artifice
Alberich then appears and reveals his plans;
Alberich:...I plan to work wonders -
However he is tricked by the cunning Loge and captured. He is taken back to the upper world and there forced to disgorge his treasure. In addition, Wotan requires him to surrender the Ring202. This is accompanied by the hideous curse that Alberich lays upon the Ring.
Alberich:...As it came to me through a curse,
Thus Wotan, in taking the Ring, is doubly cursed. He has forsaken love, and he is subject to Alberich's curse of the Ring. His danger is presaged by Erda the Earth-mother;
Erda: Yield, Wotan, yield!
But Wotan does not hold the Ring for long. It passes to the giants as part of the fee for Valhalla, and in an argument that follows, Fafner kills Fasolt, and departs with the hoard, Tarnhelm, Ring and all. He uses the Tarnhelm to assume the shape of a hideous dragon, and re-appears in Siegfried.
The nature of the Ring is further revealed in Wotan's aria to Brunnhilde where he says;
Wotan: When the pleasure of youthful
The woman is Grimhilde, queen of the Gibichungs and Alberich's child referred to by Wotan is Hagen who appears as Siegfried's nemesis in Gotterdammerung.
The future lies in the hands of Siegfried, a young man who knows no fear. He is the child of the incestuous union of Siegmund and Sieglinde (both offspring of Wotan) and he is raised by Mime. He reforges the magic sword Nothung and slays the dragon Fafner, and takes the Ring. It has been Mime's plan to poison Siegfried and take the Ring for himself, but Siegfried is warned of this by a forest bird whose speech he can understand, having tasted the blood of Fafner, a drop of which fell on his finger. He slays Mime and then goes forth to release Brunnhilde the Valkyrie whom Wotan has cast into sleep and surrounded by Magic Fire. Only a hero without fear will win her.
Siegfried is the classic hero. He resembles Parsifal in his child-like simplicity. He is a child of nature, able to understand the natural world and the speech of birds and animals. He cannot be wounded except in the back, an attribute that is given him by Brunnhilde. He is fearless, and accordingly would turn his back on nothing. He is the salvation of the world. As Wotan says;
"Alberich's curse is impotent
Although Siegfried is the classic hero, and wins Brunnhilde, the machinations of Hagen lead to his downfall. He is eventually slain, and Brunnhilde in grief at deception and realisation that she too has been a victim of Hagen's dealings, leaps into Siegfried's funeral pyre with the Ring. The fire leaps up to consume Valhalla, and the Rhine breaks its banks. The Rhinemaidens triumphantly recover the Ring and their lost gold, and the inference is that the world is renewed.
In essence, therefore, Wagner's Ring is about the power of love juxtaposed against the love of power. It has also been described as the rape of the purity of Nature in the pursuit of power. Whatever power the Ring has, any evil associated with it comes from without, or from the curses. Unlike Sauron's Ring, it does not have or possess the evil power of its maker. In addition, there are no associated Rings over which it has control.
The Ring is not inherently evil. But whoever takes the Ring takes it subject to its curses. In addition, the Ring functions as a means to power. It is the love of power that attracts. It does not have the addictive qualities that are manifested in Gollum, Bilbo and Frodo. But it does have power inherent within it. But that power must be evil, for there is no love associated with it. The power that is given by the Ring could not be used for a beneficial or altruistic purpose, since such purpose requires love as a pre-condition. This being so, there is no matter in contention about the Ring. It is claimed by both Gods, Men and Nibelungs. The Wagnerian cosmos is somewhat simplistic207and there is no essential conflict between Good and Evil. The Gods, Nibelungs and Men are flawed. Tolkien's cosmos and creation in The Lord of the Rings is far more detailed, being part of an overall created mythology, with all of the major cosmological ingredients present. The Elves, as preservers and protectors of creation are not present, although reference is made by Alberich to Wotan as "lichtalben" (light-elf) and to himself as "schwarzalben" (dark-elf).208 Beyond this, any similarity ceases. There arises no issue regarding the destruction of Wagner's Ring, for it is not seen as wholly evil. The issues are whether or not a person will take it subject to its curses and by doing so deny their humanity, and whether the Ring should return to the Rhine whence the Gold came.
Wagner's Ring induces in those who do not have it, a lust to possess it. But it has no animus of its own. It is not irretrievably bound to its Maker. The power that is within it is a magical power derived from its source - the Rhinegold.
It is perhaps simplistic to say that the only similarity that the two Rings have is that they are round, and in saying that I believe Tolkien was being dismissive of Wagner's dealings with German myth. There are similarities, but they are broad and general similarities. Both the Rings are symbols of power and carry power within them. Both the Rings carry with them an ability to inspire a lust for power upon those who do not possess them. Possession of the Ring carries a price to be paid. To take the Ring is an exercise in choice.
Both Tolkien and Wagner were aware of and drew upon the Norse and Teutonic myths. The names of the dwarves in The Hobbit appear in the Poetic Edda, which was one of Wagner's sources, along with the Volsungasaga and the Niebelungenlied. The incestuous union between brother and sister is a common theme in other Northern European myths209, and appears in the Tale of Turin Turambar in The Silmarillion.
Any student of Northern European and early Teutonic culture would be aware of the importance of the "finger-ring" as a token. It was not only a means of adornment, but had a very special significance. Rings were regarded as treasure or wealth. They had a social status. Rings were prized as gifts, to be given and received. That Sauron uses the Rings that he gives to enslave indicates a perversion of the traditional basis of exchanging rings. Rings were then, as now, exchanged in marriage, and were material signs of welcome. Two rings feature significantly in the Norse tales - Draupnir, which appears in the prose Edda, and Andvaranaut (Andvari's Ring) which features in the tale of Ottar's Ransom and which appears in the Prose Edda and the Volsungasaga.
The concept of the Ring as giving the owner mastery of the world was Wagner's own contribution to the myth of the Ring. This power would attract to any wielder of the Ring. Tolkien's Ring gave power according to stature. Gollum could not have ruled the world with it. The evil that was present in Wagner's Ring flowed from the rejection of love (the curse of the Rhinegold) and the destruction of the wearer (Alberich's curse). Wagner could not conceive that man would reject love, but the lust for gold and the power that it brought was a powerful motivator, possibly the strongest after love. Thus, Wagner posits one primal desire against another. Tolkien's Ring works far more subtly, playing upon the desires and wishes and particular motives of those who come upon it.
In terms of creative background, both Rings have a common ancestry and, as ingredients of a mythological setting, have certain symbolic similarities. But it is quite clear that Tolkien's work owes nothing to Der Ring des Nibelungen, and it is impossible to draw comparisons between the two works. The few similarities that there are operate as faint and disparate echoes of one another, coming from a distant and common source.
One Ring to Rule Them All by David Harvey
The Tolkien Encyclopedia
The Art of Tolkien
One Ring to Rule Them All by David Harvey
Hypertextual System by FMI Publishing, 1995