Duration and frustration. The characteristics that define Charles Burnett’s magisterial “Killer of Sheep” are equally relevant in describing the film’s unlikely journey to its first full-fledged theatrical release. About 30 years after Mr. Burnett shot his debut film in the working-class Los Angeles neighborhood of Watts, and 17 years after the Library of Congress chose it for its National Film Registry of American classics, “Killer of Sheep” makes its premiere on New York screens with a run at the IFC Center beginning today.

Long held from commercial distribution by the exorbitant cost of acquiring the rights to its soundtrack, “Killer of Sheep” emerges from the shadows courtesy of Milestone Films and the UCLA Film & Television Archive, which has restored the original 35 mm print to its original splendor.

Mr. Burnett — along with fellow directors Haile Gerima, Billy Woodberry, and Julie Dash — was part of the first generation of black filmmakers to emerge from the UCLA film school in the late 1960s and early ’70s. Together with his colleagues, Mr. Burnett (who would go on to make “My Brother’s Wedding” in 1983 and “To Sleep With Anger,” in 1990, both of which will be released on DVD by Milestone later this year) found poetry in the tedium of daily life — a discovery that forms the backbone of “Killer of Sheep.”

Concentrating on the lives of slaughterhouse worker Stan (Henry Gayle Sanders) and his wife and children, the episodic “Killer” balances the unflinching realism of Stan’s workplace life against the mundanity of home.

Shooting during a year of weekends in 1972 and 1973, Mr. Burnett (who would eventually submit the final product as his UCLA thesis film) utilized friends and locals for his cast and crew, making a strength out of a potential weakness by treating each scene as a free-standing movement, a repetition and intensification of an already-stated theme. Indeed, the film proceeds like a work of music. With its overstuffed R&B soundtrack underscoring almost every scene, “Killer of Sheep” treats its music as both commentary track and Greek chorus. Dinah Washington’s “This Bitter Earth,” in particular, becomes a theme song for the film’s characters, its wellsprings of anger and optimism an expression of the film’s deepest sentiments.

In the film’s original print, “This Bitter Earth” appeared only once. But after failing to acquire the rights to Washington’s “Unforgettable,” which had closed the film, Mr. Burnett decided to reprise the song, which played during a touching scene in which Stan and his wife (Kaycee Moore) dance in their living room — an aesthetic decision that links home and work as twin founts of frustration, and subdued hope.

The action, when it comes, is muted. Stan muddles through day after day at his unpleasant task, leading sheep by the thousands to the slaughter, his own life draining out onto the abattoir floor along with the animals’ blood. Opportunities abound for potential success and for momentary escape, but ultimately they prove to be little more than empty promises. Everything, from economic advancement to sexual pleasure to a country getaway, is impeded, blocked, prevented from blossoming. Frustration is the film’s oxygen, and Stan breathes deeply of it in every scene, with his own sense of stunted prospects infecting his family in turn.

In one remarkable, iconic scene, Stan and his buddy Bracy (Charles Bracy) go to an acquaintance’s home to buy a car engine. After a lackadaisical round of negotiations concludes, Stan and Bracy commence shlepping their newfound prize home. As each takes one end of the engine, the two gingerly make their way down the stairs, one step at a time. Mr. Burnett cuts from a close-up of their hands on the engine to a street-level shot that takes in the immensity of the task they’ve set for themselves. After finally getting it down the stairs, Stan and Bracy shove the engine partway into the back of their pickup truck before Bracy mashes his finger beneath its mass. Insisting that they leave the engine as it lies, Bracy begins driving off, leaving it to smash down on the pavement.

Mr. Burnett’s interest in duration — his realist’s desire to depict the entirety of an act, rather than a Hollywoodized segment — pays its largest dividends in this scene, in which labor has lost not only its esteem but its very purpose. Stan sweats, but the fruits of his labor are meager and tasteless. Meanwhile, his wife is left to subsist on his scanty affections, and his son (Jack Drummond) recreates, along with his friends, a vanished world of honorable labor in Watts’s abandoned lots.

Celebrating and honoring a segment of Los Angeles, and a subsection of its residents, rarely seen before onscreen, “Killer of Sheep” is a love song to the city from a native son — one who knows it, if anything, all too well. The film’s sense of frustrated ambitions, of lives stunted in their striving for growth, burned itself so indelibly into celluloid that it singed the film itself, keeping it little more than a rumor and a word-of-mouth phenomenon for 30 years. Its ambitions frustrated no longer, “Killer of Sheep” can now be fully appreciated for what it is: a landmark in the history of American realism, a classic film of black life, and nothing less than a masterpiece.