After the ludicrous “Youth Without Youth,” Francis Ford Coppola continues his downward spiral with this florid melodrama about a highly dysfunctional family. The old-fashioned tale could be taken for a lesser work by John Steinbeck in his “East of Eden” period, and the fifties feel is accentuated by the director’s decision to shoot it mostly in black-and-white (the flashbacks are in color). But the splashily flamboyant technique—as much visual overkill as in “One from the Heart”—and goofy philosophizing about creativity and genius is pure, unadulterated Coppola. It’s another deeply embarrassing misfire from a man once considered a major American filmmaker.

The narrative begins with Bennie (newcomer Alden Ehrenreich) arriving in Buenos Aires as a waiter on a cruise ship. He’s come to look up his long-lost older brother, now calling himself Tetro (Vincent Gallo), who fled their home years earlier leaving a note promising to return for his beloved younger sibling—a promise he failed to keep. It turns out that Tetro, a shaggy, abrasive fellow, has pretty much abandoned his writing career and is living with vivacious girlfriend Miranda (Maribel Verdu), occasionally operating the lights at a run-down local theatre run by a womanizer named Jose (Rodrigo De La Serna), where a would-be avant-garde playwright named Abelardo (Mike Amigorena) puts on scandalous shows. He certainly offers no welcome to Bennie, who’s puzzled and saddened by his dismissive attitude.

But when Bennie’s ship suffers a mechanical problem that delays its departure, Tetro reluctantly allows him to stay in his apartment, which allows Bennie to find—and decipher—his brother’s unfinished manuscripts. They reveal—through those color flashbacks—the abusive treatment Tetro suffered from the boys’ dictatorial father, famed orchestral conductor Carlo (Klaus Maria Brandauer), including the final indignity that caused him not only to flee the house but, as we eventually learn, to keep a terrible family secret ever since (a secret that many viewers will have guessed long before Coppola chooses to tell it to us).

By the time that revelation is sprung, though, Bennie has suffered an accident that prevents him from leaving and, after another dustup with Tetro, gives him the opportunity to finish his brother’s uncompleted play and get it accepted as their joint work into the Patagonia Festival, a prestigious arts competition run by the country’s greatest critic, a spectral woman who calls herself Alone (Carmen Maura) and has long dismissed Tetro for failing to realize his full potential.

That sets the stage for what’s easily the worst part of the picture—a couple of ludicrously operatic sequences that reek of pomposity and empty visual ostentation. The first involves the Festival presentation of a scene from the brothers’ play—which earns wild cheers from the starry crowd but is by any measure incredible rubbish. (This is the point at which Tetro’s big revelation also occurs, sending Bennie into an emotional tailspin.) But even that is topped by the sudden announcement of Carlo’s death, which occasions a nutty funeral scene that casts the collapse of the house as though it were the fall of Valhalla in “Gotterdammerung” (though the music is by Brahms, not Wagner).

This is all old-fashioned melodramatic claptrap, served up in ridiculously overblown style. It does have a few virtues. Despite the absurdity of the material, Ehrenreich proves an engaging presence and may be a real find. Verdu is better than the script deserves as well. And though the visual flamboyance has an annoying “look at me” quality, the technical work is impressive, especially given the obviously modest budget. Mihai Malaimare Jr.’s widescreen cinematography has a luminous quality, and the overall production design by Sebastian Orgambide hides the budgetary limitations skillfully.

But while not as pretentious and impenetrable a dish as “Youth Without Youth,” “Tetro” is equally indigestible.