The late opera composerCarlisle Floyddid occasionally turn his sights elsewhere, but the bulk of his work was steeped in the sounds and stories of the United States. That was true of his most enduring legacy,“Susannah,”and it was true of his 1970 opera “Of Mice and Men,” which opened in a powerful production over the weekend at the Livermore Valley Opera.

Like John Steinbeck’s classic novella, Floyd’s opera — for which he wrote his own libretto — is a strong-boned tearjerker. It’s a story about love between men that scrupulously avoids any hint of homoeroticism in favor of a rough-hewn but affecting fable. It also persuades you that Depression-era California isn’t merely Steinbeck’s chosen stomping ground but a microcosm for the human condition.

The Livermore production, nimbly directed by Marc Jacobs on designer Jean-François Revon’s evocative blend of stage sets and sumptuous visual projections, takes the opera at its word.

The plight of the migrant ranch hands George and Lennie, with their modest dream of owning a little farmhouse on a couple of acres where they can raise chickens, takes on an ambitious sense of scope. So do the obstacles in their way, beginning with the feeble-minded Lennie’s overpowering physical strength and ranging as far as the heedlessness of the world itself.

That’s a lot to pack into a three-hour opera, but the matinee performance at Livermore’s Bankhead Theater on Sunday, Oct. 8, the second in a four-performance run, took the piece’s measure skillfully. Both dramatically and musically, the performance captured Floyd’s brand of heightened realism, as if the migrant mother inDorothea Lange’sfamous photographwere to give voice to her predicament in song.

与音乐导演亚历山大Katsman主审机汇er a reduced orchestra, Floyd’s score emerged with all its sharp lineaments in profile, from the busy, almost cinematic episodes of scene-setting to the tender solos in which the characters lay out their situation.

At the vertex of the drama was baritone Robert Mellon’s rich-hued and expressively complex portrait of George. George is our protagonist throughout, the one who shoulders the burden of making his way through life while tending for — and caring deeply for — the incapable Lennie. The first aria Floyd gives him reflects his unattainable dream of being free of that obligation, and Mellon’s magnificent delivery created a lasting moral framework for the entire piece.

Matthew Pearce was no less formidable as the hulking, heedless Lennie, his powerful tenor cresting in moments of jubilation, then turning in on itself in a panic when the character’s brute instincts land him in trouble.

Bass Kirk Eichelberger was a robust, winning presence as Candy, the older ranch worker who becomes the two men’s chief ally.

There is just the one female presence in this otherwise all-male undertaking, the Eve-like temptress known only as Curley’s Wife. We can pin the sexual politics on Steinbeck, while noting that Floyd gives this lonesome, unhappy woman a voice of her own, and that soprano Véronique Filloux dispatched her assignment with precision and a modicum of pathos.

Livermore Valley Opera, run by the retired soprano Erie Mills, continues to do inventive work in a setting where another impresario might settle for endless retreads of the standard operatic repertoire. “Of Mice and Men” is emblematic of that lively spirit.

Reach Joshua Kosman:jkosman@sfchronicle.com