So, I am happy to have just read a discussion of this from The New Yorker in 2003. Some quotes, but you should go read the whole thing:
Tolkien refused to admit that his ring had anything to do with Wagner’s. “Both rings were round, and there the resemblance ceased,” he said. But he certainly knew his Wagner, and made an informal study of “Die Walküre” not long before writing the novels. The idea of the omnipotent ring must have come directly from Wagner; nothing quite like it appears in the old sagas. True, the Volsunga Saga features a ring from a cursed hoard, but it possesses no executive powers. In the “Nibelungenlied” saga, there is a magic rod that could be used to rule all, but it just sits around. Wagner combined these two objects into the awful amulet that is forged by Alberich from the gold of the Rhine. When Wotan steals the ring for his own godly purposes, Alberich places a curse upon it, and in so doing he speaks of “the lord of the ring as the slave of the ring.” Such details make it hard to believe Tolkien’s disavowals. Admit it, J.R.R., you used to run around brandishing a walking stick and singing “Nothung! Nothung!” like every other besotted Oxford lad.Now here is a crucial take on what I might now take to calling "the real Ring" to annoy Tolkien fans:
It is surely no accident that the notion of a Ring of Power surfaced in the late nineteenth century, when technologies of mass destruction were appearing on the horizon. Pre-modern storytellers had no frame of reference for such things. Power, for them, was not a baton that could be passed from one person to another; those with power were born with power, and those without, without. By Wagner’s time, it was clear that a marginal individual would soon be able to unleash terror with the flick of a wrist. Oscar Wilde issued a memorable prediction of the war of the future: “A chemist on each side will approach the frontier with a bottle.” Nor did the ring have to be understood only in terms of military science. Mass media now allowed for the worldwide destruction of an idea, a reputation, a belief system, a culture. In a hundred ways, men were forging things over which they had no control, and which ended up controlling them.
There is a widespread conception of Wagner’s cycle as a bombastic nationalistic saga in which blond-haired heroes triumph over dwarfish, vaguely Jewish enemies. Wagner unquestionably left himself open to this interpretation, but the “Ring” is not at all what it seems. It is in fact a prolonged assault on the very idea of worldly power, the cult of the monumental—everything that we think of as “Wagnerian.” At the beginning, the god Wotan is looking to expand his realm. But every step he takes to assert himself over the affairs of others, to make his will reality, leads inexorably to his downfall. He is marked from the outset, and the ring becomes a symbol of the corruption of his authority. Tolkien believes in the forces of good, in might for right. Wagner dismisses all that—he had an anarchist streak early on—and sees redemption only in love.This is fantastic! It's giving me a whole new explanation as to why I didn't respond to Lord of the Rings - because it makes no, um, meta-emotional sense, to coin a phrase. Back to what the real Ring - heh - is about:
When Tolkien stole Wagner’s ring, he discarded its most significant property—that it can be forged only by one who has forsworn love. (Presumably, Sauron gave up carnal pleasures when he became an all-seeing eye at the top of a tower, but it’s hard to say for certain. Maybe he gets a kick out of the all-seeing bit.) The sexual opacity of Tolkien’s saga has often been noted, and the films faithfully replicate it. Desirable people appear onscreen, and one is given to understand that at some point they have had or will have had relations, but their entanglements are incidental to the plot. It is the little ring that brings out the lust in men and in hobbits. And what, honestly, do people want in it? Are they envious of Sauron’s bling-bling life style up on top of Barad-dûr? Tolkien mutes the romance of medieval stories and puts us out in self-abnegating, Anglican-modernist, T. S. Eliot territory. The ring is a never-ending nightmare to which people are drawn for no obvious reason. It generates lust and yet gives no satisfaction.
Wagner, by contrast, uses the ring to shine a light on various intense, confused, all-too-human relationships. Alberich forges the ring only after the Rhine maidens turn away his advances. Wotan becomes obsessed with it as a consequence of his loveless marriage; he buries himself in his work. Even after he sees through his delusions, and achieves a quasi-Buddhist acceptance of his powerlessness, he has nothing else to lean on, not even his Gandalfian staff, and wanders off into the night. Siegfried and Brünnhilde, lost in their love for each other, succeed in remaking the ring as an ordinary trinket, a symbol of their devotion. They assert their earthbound passion against Wotan’s godly world, and thus bring it down. The apparatus of myth itself—the belief in higher and lower powers, hierarchies, orders—crumbles with the walls of Valhalla. Perhaps what angered Tolkien most was that Wagner wrote a sixteen-hour mythic opera and then, at the end, blew up the foundations of myth.Cool.