Minnesota Concert Opera's "Mini-Ring," a 3½-hour condensation of Wagner's 15-hour "Der Ring des Nibelungen," is quite an achievement. Arranger David Seaman created a seamless flow of music, but in cutting more than three quarters, the losses weighed heavily.

He was wise to cut the orchestral set pieces (no "Entry of the Gods into Valhalla," or "Ride of the Valkyries"), because the chamber ensemble (not large enough to be considered an orchestra) would have been unable to do them justice.

But he cut most of the vocal set pieces as well. And there are no Valkyries, no Norns, no Erda. Each of the eight singers played multiple parts.

His adaptation is narrative-driven, moving from plot point to plot point, making this "Ring" feel like a summer action movie. The deeper elements that make it a great work of art were missing.

At the same time, the performance was compelling, keeping my attention in a way that the full "Ring" might not have.

Projections, designed by Jeremy Knight, evoked the locations of the action. And supertitles, designed by conductor Jonathan Khuner, translated the libretto, but also laid out the missing action.

Khuner, an experienced Wagnerian, held the performance together, making all the pieces feel like a coherent whole.

The singers worked from behind music stands, but that did not hinder Richard Paul Fink's Alberich. Beyond his gleaming baritone, he created the most complex and theatrical character, fully engaged in every moment.

As Brunhilde, Lori Phillips, ably substituting for an ill Jane Eaglen, had a soprano that soared easily through the heights of the role. She successfully conveyed the character's transition from goddess to woman, and her rage at being betrayed by Siegfried was a dramatic highlight.

Philip Skinner had a resounding bass-baritone as Wotan, but he was dramatically inert. He seemed unable to look up from his score.

Jay Hunter Morris' strong tenor made the most of Siegfried's music, but his performance verged on caricature. His relationship with Brunhilde, rather than passionate, seemed cute and coy.

It is likely to be years before there is the chance to hear Wagner's "Ring" live again locally. So for all the limitations of the presentation, I'm grateful that I was able to have the experience.

William Randall Beard writes about music and theater.