In many configurations, they make for very treacherous terrain.

Like pediments on a Greek temple, they are flat on one side and bent on the other, and their sculptural potential is just about boundless. In point of fact, those so-called planks are not planks at all but slabs in the form of a shallow isosceles triangle.

As you will have heard before, it consists of 24 identical “planks” mounted side by side on a horizontal axis that moves up and down, not from left to right. This time, the issue is technology, specifically the show’s notorious 90,000-pound omnipresent centerpiece, universally known as The Machine. As a rule, such claims have to do with ideas. Peter Gelb, the company’s general manager, has been suggesting of late that the Lepage Ring was ahead of its time. Tomasz Konieczny as Alberich in ‘Das Rheingold.’ After an absence of six seasons, it’s back. The production, by Robert Lepage, found few if any champions but many merciless detractors.

By 2012, the four segments of Wagner’s mythopoeia were in readiness for presentation as a cycle, an instant replay following a year later. The rollout began with Das Rheingold in the fall of 2010. NEW YORK – The “new” Ring des Nibelungen at the Met is, alas, a fixture now. (Photos by Ken Howard / Metropolitan Opera) By Matthew Gurewitsch Christine Goerke (Brünnhilde) and Andreas Schager (Siegfried) in the Metropolitan Opera production of ‘Götterdämmerung.’

The ring at the metropolitan opera