Look at a list of the world’s 100 highest mountains, and you’ll probably be struck by how few of them you know beyond Everest, K2 and Annapurna. It’s a perfect analogy to classical music: The giants are in the popular consciousness, and Everest is horribly over-trafficked, but there are so many nearly comparable works that are overlooked, though they form a key part of the whole magnificent landscape.

Wolf Trap and the Washington Concert Opera tackled one of those smaller mountains last weekend: “Le Vin Herbé” (“The Magic Potion”), by the 20th-century Swiss composer Frank Martin. “Le Vin Herbé,” premiered in 1942, audaciously takes on an Everest upfront. It’s based on the medieval legend of Tristan and Iseut, the basis for Wagner’s 1859 opera “Tristan und Isolde,” which Gianandrea Noseda, the music director of the National Symphony Orchestra, recently described to me as the major watershed in Western classical music.

Martin deliberately went in a completely different direction, creating a dramatic oratorio in which a lot of the action is narrated by a chorus, for an eight-piece orchestra, and going back to the source material to create his own version of the story. Given how different the details are, it’s striking how many of the peaks remain the same, from the shipboard setting of Act I, when Iseut, fuming at being sent off to marry King Marc, accidentally drinks the love potion with Tristan, to Act III, when the mortally wounded Tristan awaits Iseut, who comes too late and dies across his corpse.

Even the soundscape arrives at a similar place along a different route. Both scores are densely chromatic — crowded with pitches, that is, outside their proper tonality — but where Wagner arrives at that through incredible richness of instrumental and vocal means, Martin’s starting point is a place of spareness, even austerity. There’s a ritualistic element to all theater — opera has its roots in the sung and danced dramas of ancient Greece — and Martin harks back to that deliberately by seeming to eradicate traces of melodrama and presenting his work as a kind of enacted narrative, with the soloists emerging from a chorus that serve as troubadours, beginning and ending the work with addresses to the audience. Yet the emotion and richness of the music seep through, and we also find ourselves in a dreamscape, though of more Debussy-an than Wagnerian hues.

Appropriately enough to the spirit of this work, the leads in the production at Wolf Trap appeared to have stepped out of a pre-Raphaelite painting: soprano Shannon Jennings with a serpentine head of auburn hair, and blond tenor Ian Koziara the incarnation of a Nordic knight. More important, they both brought to their roles tremendous dramatic intensity — Jennings was able to register her reaction to Tristan’s death while standing motionless, only through the expression of her face — and vocal ability. Koziara, who already showed his mettle as last summer’s Idomeneo, sounded here as if he needed a little more work on the very top notes, but the rest of his voice was firm, assured and nearly baritonal. The Marc, Joshua Conyers, has been developing admirably at Wolf Trap and in the Domingo-Cafritz program, gaining in authority and vocal power each time I hear him. Summer Hassan was a strong Branghien, and Nicole Thomas projected a touching innocence as Tristan’s wife, also named Iseut.

Antony Walker stood before the chamber ensemble at the side of the stage and conducted effectively in an idiom far removed from the bel canto bounce that Washington Concert audiences have seen him do so often. The ensemble, seven strings and a piano, made every note count. One reason that less-known works are staged less often is that it’s hard to find the right way to present them: “Le Vin Herbé” is a chamber or radio opera that wouldn’t fit in a large opera house. But for both Wolf Trap and Washington Concert Opera, which make a point of exploring wider segments of the terrain, it was just right.