BAYREUTH, Germany — Richard Wagner’s opera tetralogy “Der Ring des Niebelungen” has been staged in a variety of ways at the Bayreuth Festival over the past 130 years. There have been classical “Rings” of picture-postcard beauty, high-concept “Rings” suggesting the Victorian-era Industrial Revolution and minimalist “Rings” on virtually bare stages.German scribe-director Tankred Dorst, who at 80 had never before directed an opera, promised to return the “traditional ‘Ring’ ” to Bayreuth. But his basic idea — that the gods are eternally among us, we just don’t see them — is so rarely touched upon, he created a no-concept production. There’s never any indication in Dorst’s production of “Gotterdammerung” that the passive mortals strolling the stage in contemporary dress are even vaguely affected by the passionate story of clashing deities and apocalypse going on around them. Wagner demands special effects: a rainbow bridge to carry the gods to Valhalla, the magic fire that encircles the sleeping Brunnhilde, a dragon and the eventual apocalypse in flames. Dorst’s recurring solution is to flood the stage with smoke and hit it with primary-colored spots. Blame the arrival of Dorst on fest director Wolfgang Wagner — and, to some degree, Lars von Trier. Wolfgang, Richard’s 87-year-old grandson, whose role is now being contested by many family members, has opened the doors to an adventurous new generation of stage directors. It began with Patrice Chereau’s centennial “Ring.” And in 2004, “Parsifal” from provocateur Christoph Schlingensief, featuring voodoo rituals and a time-lapse film of a decomposing hare, made front-page news. (It was also widely jeered). Von Trier was tapped for the 2006 “Ring,” but he resigned two years ago and was replaced by Dorst. Regardless of the quality this year, Bayreuth, with its theater in a park atop a hill in rural Bavaria, and Salzburg remain the two most important opera festivals in the world. Bayreuth’s popularity can be found in its waiting list to buy tickets: The average wait is currently 10 years to plunk down $1,060 to see productions of Richard Wagner’s seven mature operas. Productions run for about six years, but in 2008 Bayreuth will debut a new “Parsifal.” The premiere next year will be “Die Meistersinger.” The casts were once the Who’s Who of opera; stars have largely stayed away for the past decade. But there were some notable names performing rather well in this year’s “Ring” cycle. Falk Struckmann’s intense, thrillingly sung Zeus-like Wotan was matched by American tenor Stephen Gould’s Siegfried, better suited to the role’s superhuman demands than anyone in recent memory. Hans-Peter Konig’s spine-tinglingly evil Hagen was the stuff of nightmares. Michelle Breedt was an elegant incarnation of Wotan’s wife Fricka, and Adrianne Pieczonka a lustrous Sieglinde. Robert Dean Smith, another American tenor currently wowing them at the festival in the demanding lead in “Tristan und Isolde,” jumped into the role of Siegmund when Endrik Wottrich’s voice gave out midway into act one of “Die Walkure,” delivering one of the most memorable performances of this frustratingly uneven production. On the other hand, in the punishing role of Brunnhilde, Linda Watson showed a big voice in a state of disrepair, characterized by a wobble and pitch problems. State-of-the-art backstage technology did not help the production. Frank Philipp Schlossmann’s unyieldingly gray sets were grungy and bland and Bernd Skodzig’s egregiously ugly costumes looked like rejects from “X-Men.” Conductor Christian Thielemann didn’t improve matters. He seemed content to just draw pretty sounds from the superb Bayreuth Festival Orchestra. Including intermissions, this year’s “Ring” clocked at just a few minutes shy of 21 hours. That’s a considerable amount of time to spend with the most dispassionate Wagner this critic has ever encountered.