Although the four operas have shown separately, Tuesday was the concluding night of a first marathon session in which audiences could watch all 16 hours' worth of performances in a period of just two or three weeks.
Ever since Richard Wagner, who lived from 1813 to 1883, composed the extraordinary work, it has seen countless productions and become embedded in Western culture. What the Met is doing for the first time is in effect to add a new protagonist: the set.
Unofficially dubbed "the machine," it is a huge, moving structure of 24 aluminum planks that resemble a weirdly active piano keyboard.
At 45 tons, it is minimalist but multi-purpose, allowing Lepage to conjure rivers, woods and mountains with nothing more than moving boards.
Although the opera is set in a mythical landscape, the performers appear to have emerged from science fiction films such as "Blade Runner" and "Star Wars."
The cast is highlighted by Welsh baritone Bryn Terfel playing Wotan, US soprano Deborah Voigt as Brünnhilde and US tenor Jay Hunter Morris as Siegfried. Italy's Fabio Luisi conducts the orchestra.
The choreography features moments of extraordinary visual beauty, such as the dance of nymphs at the start of "Das Rheingold," with dancers floating in front of what appears to be water tumbling down the "machine's" now vertical planks.
Another sublime scene sees the famous "The Ride Of The Valkyries", a part of "Die Walküre," in which the metal planks become the demigods' horses as they gather up fallen heroes on battlefields to bring them to Valhalla.
But Lepage's ambitious device and production in general have come in for torrents of criticism for being clunky and overwhelming.
"Pound for pound, ton for ton, the most witless and wasteful production in modern operatic history," the New Yorker wrote.
But for the Canadian director, rethinking the Wagner cycle is a once in a lifetime opportunity.
"I try to be extremely respectful of Wagner's storytelling, but in a very modern context. We're trying to see how in our day and age we can tell this classical story in the most complete way," he said in a statement on the Met's website.
"The Ring is one of these rare opportunities that you get to work on such a huge undertaking. It's not just a story, it's not just an opera or a series of operas: it's a cosmos."
Wagner spent 26 years writing the three-part cycle, combining German mythology and an epic medieval poem to tell the story of the struggle for a magical golden ring that will give power to dominate the world.
"Der Ring Des Nibelungen," as the work is collectively titled, made its debut in 1876 in Bayreuth, Germany, where there is a theater specially constructed for Wagner music.
The ongoing Tribeca Film Festival in New York, meanwhile, is showing "Wagner's Dream," a documentary about the Lepage production.
"Shot over five years, filmmaker Susan Froemke's behind-the-scenes documentary captures unprecedented challenges of bringing Lepage's electrifying production to life," publicists said.
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