Conductor Antony Walker, Michelle DeYoung and Greer Grimsley in the Washington Concert Opera performance of “Samson et Dalila.” (Stan Engebretson/Washington Concert Opera)

For an opera about an action hero, Camille Saint-Saens’s “Samson et Dalila” is remarkably action-free: Even the climactic moment when Delilah shears the hero’s hair takes place offstage. It’s open to question whether its stasis makes it better suited to a concert performance than some other operas, or whether it needs a little stage business — costumes, sets — to help liven things up.

The Washington Concert Opera took the gamble Saturday night by offering it in concert format under Antony Walker, albeit with at least one piece of real-life visual enhancement: The male leads, Frank Poretta and Greer Grimsley, both had genuine ponytails. Had Michelle DeYoung’s Delilah dared to actually clip Poretta’s hair, we would have ventured into the territory of verismo.

Instead, the terrain was the vaguely Oriental world of Saint-Saens’s big, sensuous sound — a sound that was a little beyond the abilities of the Washington Concert Opera Orchestra to fully realize in the confines of Lisner Auditorium, despite Walker’s best efforts. Walker is one of those marvelous musicians who throws himself heart and soul into everything he does. Watching him conduct the Bacchanale, the priests’ dance in the final act, you could almost have believed it was a piece of significant music rather than a pops-concert potboiler — almost, but not quite. The orchestra did quite well, but you want a slightly richer sound to convey this languid, dreamy music.

And you want slightly richer voices. The WCO was banking on Brandon Jovanovich, a rising young tenor sensation and Richard Tucker Award winner, who’s been moving into ever heavier repertory. Jovanovich, alas, wound up with swollen vocal cords at the end of his successful run in Dallas’s “Don Carlo,” and he is on doctor’s orders for full vocal rest — meaning he canceled not only “Samson” but also a scheduled appearance with the Baltimore Symphony Orchestra later this month. This left Poretta, already heard here this season in Washington National Opera’s “Tosca,” a big burly presence with a slightly less burly voice. (His performances often leave me with a feeling of respect for hard work honorably done, but seldom leave me excited.) Grimsley, a Wagnerian, assailed the High Priest’s role with a big, wiry sound to match his tall, wiry body, cutting through the orchestra like a blade.

The real action in this opera centers on Delilah: It may be a static piece, but this character gets two of the best mezzo-soprano arias in the repertory. All you have to do is be sensuous, beautiful and voluptuous, but DeYoung supplied the visuals a bit more than she did the sound. Singing onstage with a full orchestra is a huge challenge, one DeYoung has already taken on in the District once this year in Bartok’s “Bluebeard’s Castle” with the National Symphony Orchestra; here, she tended to push the voice enough to create a wobble that carried it slightly off the pitch at key moments. She executed the arias adequately, but I found more interest in her duets, particularly with Grimsley, which are less often excerpted but which gave rise to more sparks.

There’s a lot of French opera going around Washington this month; WNO had just opened Massenet’s “Werther” the night before. Kenneth Kellogg, a member of the Domingo-Cafritz program, stepped from one straight into the other, taking on the role of Abimlech from memory but briefly stumbling. He’s a fine singer, though, and his character’s death spared him from further challenges. J. Austin Bitner, Matt Osifshin, Patrick Toomey and Liam Moran filled the other small roles, mainly acting as foils to announce more offstage action, then taking their places again in the chorus, which, though again slightly sparser than the ideal, acquitted itself well.

The audience was generally approving, but “Samson” remains something of a stretch for everyone. Next year, WCO will return to what’s evidently its most popular fare, a double helping of bel canto opera with Bellini’s “La Sonnambula” and Donizetti’s “Maria Stuarda,” vocal pyrotechnics over a slim orchestra. But you have to hand it to the orchestra for trying.