The hero of the opera was a dog. Samuel Weiser, a bass, wore a full-size dog costume, black-painted nose and all, to depict the eponymous hero of “Pepito,” a shelter dog dreaming of his old life and his new one. “Are you the right dog? Are you the one?” asks Camila, a harried lawyer in a frustrating marriage, arriving at the shelter to find a pet. “I don’t know,” responds the dog helpfully. “I love you.”

It’s the season of short new operas at the Washington National Opera. For the seventh time, the annual American Opera Initiative this weekend presented a new one-hour work (on Friday and Sunday) and three 20-minute operas, twice each, on Saturday night. The program allows the company to commission new work without the punishing expense and risk of mounting a mainstage opera (the works were all presented in the Terrace Theater, in semi-stagings). It also lets it try out a number of different composers, such as Matt Boehler, himself a bass, who wrote “75 Miles” with the librettist Laura Barati, in which a 16-year-old girl talks to her mother about her pregnancy (the nearest women’s health center, where she could get an abortion, is 75 miles away).

The showcase is the one-hour opera, for which WNO invites more-experienced composers including, last year, Missy Mazzoli, whose “Proving Up” went quickly on to other productions, and who was named, a few months later, composer-in-residence of the Chicago Symphony Orchestra. This year’s offering, “Taking Up Serpents,” was written by Kamala Sankaram, another composer whose work has been seen around the country. Her intriguing, offbeat handling of the instruments in the pit, including whirly tubes creating a synthetic hum, was the strongest thing about her piece — and set the tone in a program in which all four works showed more assurance and interest in their orchestrations than in their vocal writing, which tended to be flaccid.

“Taking Up Serpents” is about the daughter of a Pentecostal snake-handling preacher dying of a snakebite. Having tried to free herself from her unbalanced and strong-willed father, the girl returns home to see him on his deathbed and finally break free of his influence. “I am whole! Just as I am!” she cries, repeatedly, at the end, as her father dies, while her younger self, who had always been terrified of snakes, triumphantly thrusts her hand into one of their cages.

Yes, it was confusing in the house, too; and yes, it demonstrates one risk of these short-format works: they become especially subject to cliche. Opera companies put huge emphasis on the libretto when developing new work these days, but Jerre Dye’s text for this work, though supposedly reinforced by the fact that Dye actually grew up in a Pentecostal church, was generic and heavy-handed. The opera begins with a beautiful musical evocation of moths under a parking-lot light, drawn in little figures from the flute. But then the heroine, Kayla, bursts into an aria about circling moths drawn to the flame that tells us nothing specific about her as a character, nor offers any idea that hasn’t been uttered many times before. (Her opening line, “This parking lot’s a graveyard,” follows the cadence of “Ain’t it a pretty night” from Carlisle Floyd’s “Susannah,” a clear antecedent to this work in that it’s another opera set in a religious community in rural America.)

Part of the reason for cliche, I think, is the pervasive notion that opera singing is supposed to be, always, a cry from the heart. Figuring out how to integrate the singing into theater in the 21st century is admittedly a challenge. I’ve always held that opera is the ideal art form for adolescents, because you spend all your time yelling about love and anger at the top of your lungs, but somehow a ponderousness seems to creep in, all too often, to new work. The mezzo-soprano Eliza Bonet did a compelling job as Kayla’s mother, frustrated in marriage and harrowed after days of watching her husband suffer from the snakebite, finally taking him to the hospital against his will, and then smothering him with a pillow to release him. Timothy J. Bruno was also strong as the father, a defiant and troubled rebel who has a conversion moment in a parking lot when Kayla is 10. And Alexandria Shiner did what she could with the somewhat generic role of Kayla, rebelling against her parents and trying to figure out who she is, singing in a high, light soprano. None of this is especially new ground. The most interesting parts were Sankaram’s atmospheric orchestrations, brought out by Lidiya Yankovskaya in the pit.

The same generic quality afflicted some of the short works, notably “Relapse,” in which Molly Joyce’s capable music couldn’t turn the story of a young woman who’s overdosed on drugs and wakes up in the hospital into much more than the plot summary indicates. Boehler, in “75 Miles,” clearly drew on his own operatic past in sweeping tonal phrases that were pretty enough but didn’t add anything specific, for all of the effort put in by the cast, including Joshua Conyers as a sympathetic, slightly clueless father with a warm voice.

So “Pepito” got pride of place. It wasn’t just because dogs and children tend to steal the show. It was because Nicholas Lell Benavides, the composer, and Marella Martin Koch, the librettist, found a way to sketch complete characters in swift sure lines. We got, right away, the dynamic between the young couple, he a workaholic, she looking for more connection, both well sung by the bright tenor Joshua Blue and the soprano Alexandra Nowakowski. We got the officious woman at the shelter (Alexandra Christoforakis), exasperated, one could infer, by unserious would-be adopters. And we got the dog. Weiser played a person playing a dog, evoking the animal rather than crawling around on all fours; when called on to kiss Camila, rather than licking her hand, he took her in his arms and dipped her in good old-fashioned musical-comedy tradition. At the end, the clueless husband, seeing the effect the dog had on his wife, got a clue, and they all went off together. I won’t say it avoids cliche altogether. But I will say that it worked.