Three years after Brazilian chanteuse Elis Regina was found dead at age 36, having accidentally overdosed on a fatal cocktail of cocaine and Italian vermouth in São Paulo, Coca-Cola corrupted her greatest hit for an advertisement beamed to millions of U.S. televisions. Aided by the same Don Drapers who had bought the world a Coke in the 1970s, the soft-drink behemoth had recently selected a new tagline for the 1980s: Coke Is It! For a brief run in 1985, the jingle for this refreshed slogan was a cheesy power-rock take on “Águas de Março”—the bossa nova standard definitively duetted by Regina and composer Antônio Carlos Jobim on their 1974 album, Elis & Tom, and inelegantly butchered by whichever ad executive had the gall to pump it with testosterone and smother it with an American flag.

If you haven’t heard either version, choose your introduction wisely. “Águas de Março” is not just a crown jewel of Brazilian artistry, but one of the most magical crystallizations of any musical idea ever put to tape. Jobim and Regina’s alchemical duet lives in the pantheon of great jazz performances, but even on paper, the song is a masterwork of lyrical and compositional synergy. Written by Jobim in 1972 to evoke Rio de Janeiro’s early autumn rains, each verse unspools a litany of I Spy images introduced by the word é (it is, in Portuguese), which whoosh by as if suspended in floodwater. At first, Jobim’s lyrics describe objects one might predictably find washing down a gutter—“It’s stick,” Regina sings, “It’s stone.” But over a chromatic bassline and brushy levada that descends like a steady deluge, much more comes to pass: tree species native to Brazil (“caingá,” “candeia,” “peroba”), people (“João, José”), even feelings (“pouco sozinho”—the “profound mystery”). Eighty lines, one for each rainy season a composer might hope to enjoy in his lifetime, all washed away in a torrent. A pouco sozinho lies beneath the song’s repetition: “It” is all these things, but what is “it” exactly? Does Jobim’s procession of images form something larger?

Coca-Cola’s commercial rewrite has not a sou of pouco sozinho. The 60-second spot, premiered during the 1985 Super Bowl, trades Regina and Jobim’s cool delivery for a Bon Jovi impersonation, and Jobim’s naturalism for muscular phrases like “It is awesome” and “It’s showin’ ’em how.” Set to a macho montage of football players donning helmets and soldiers raising flags, it’s a comically exaggerated ’80s insult to Jobim’s subtle original, made even more grievous when you consider that this version preceded the availability of Jobim’s recording for many listeners in the United States—Elis & Tom did not receive an official stateside release until 1989, though some may have heard Art Garfunkel’s English-language cover of the song on his 1975 album, Breakaway. But if you subscribe to the idea that a botched renovation helps one appreciate the original architecture, Coke’s butchery has one thing going for it. In packaging Jobim’s ineffable “it” as a product to be sold, the advertisement both betrays and underlines the essential quality of Jobim and Regina’s rendition: its transcendent surrender to the open-ended and undefinable.

Antônio Carlos Jobim had already penned most of the songs that define his legacy as the father of bossa nova when Elis Regina showed up at his door in February 1974, three-year-old son in tow, to record Elis & Tom. “Águas de Março,” which opens that album, is Jobim’s most enduring later-career hit; most of his best-known compositions, including standards like “The Girl From Ipanema,” “Corcovado,” and “Desafinado,” all appear on his 1963 debut, The Composer of Desafinado Plays. Collaborations with artists like Stan Getz and Frank Sinatra had granted Jobim a degree of celebrity in the U.S. during the mid-to-late 1960s—Getz/Gilberto, a record he composed two-thirds of, won Album of the Year at the 1965 Grammys, and in 1967, “Francis Albert Sinatra” had boarded the bossa boat with Jobim at the helm. “In America,” Jobim reminisced in a 1987 interview, “bossa nova was much more welcome than in Brazil, where purists attacked it as an Americanized simplification of samba music.” Perhaps it’s not so surprising that Jobim and Regina cut one of Brazil’s most-beloved songs in Los Angeles. It was the first and only time that Regina would sing in the United States.

Elis Regina’s star was not as fixed as Jobim’s. It had dimmed, as many stars do, in the shadow of scandal. Nicknamed “Little Pepper” for her feistiness and “Hurricane” for her intensity, the young singer had helped usher in Brazil’s música popular brasileira movement, a strain of national pop that blossomed between the bars of a brutal and repressive military regime. But when Regina sang the national anthem at a military sporting event in 1972, fans read the act as synonymous with support of the junta. Regina claimed she performed under coercion, but the damage was done. By some accounts, Regina’s manager pitched Elis & Tom as a means to restore her reputation. By others, the collaborative album was Regina’s own idea, a special request to celebrate the 10 years since she’d signed to the label Philips. In any case, though the bossa nova craze had begun to fade in America, the 47-year-old composer agreed to record with Regina. It began with tension. Jobim and Regina’s then-husband, producer César Camargo Mariano, reportedly clashed on the details of the arrangements. Regina, separated from Jobim by an 18-year age gap, did not approach Jobim’s bossa sounds with requisite coolness.

Yet Jobim entrusted Regina with “Águas de Março” to the exclusion of other singers—“Not even Sinatra deserves it,” he reportedly told her. Perhaps he knew that a Brazilian artist could best appreciate and interpret the cultural specificity of his references. Perhaps he knew that the phrasing would sound better with a little bite. The tension latent in Jobim and Regina’s working relationship gives their rendition a mischievousness that’s sorely missed in the monotony of Art Garfunkel’s version, or the twee precision of Susannah McCorkle’s. On the 1974 recording, Jobim and Regina lob lines at each other like they’re playing dodgeball. In the final minute of the song, they begin an actual game: lopping off the tops of individual lyrics and singing only their second halves (é pedra, é o fim, do caminho, etc.). The dam breaks, and Regina splits into laughter at Jobim’s deadpan devolution into nonsense. She begins to vocalize ravenously in gurgling, giddy glossolalia. It sounds a bit like Cookie Monster trying to scat.

For me, Regina’s joyous, defiant burble is the idea at the heart of the song: that there is a kind of bliss in surrendering to life’s flow that lies beyond any human attempt at defining its meaning. Listening to it recently, I was reminded of “Meditation at Lagunitas,” a 1979 Robert Hass poem in which a speaker confronts the semiotic notion that assigning words to objects degrades them, that “each particular erases / the luminous clarity of a general idea.” “Talking this way,” he realizes, “everything dissolves: justice, / pine, hair, woman, you and I.” Everything dissolves, too, in the “Águas de Março”: sticks, stones, trees, people, pouco sozinho. Yet as a rushing river carves a canyon, each particular in Jobim’s stream shapes the luminous clarity of a general idea—the ever-present “it,” a concept informed by seasons and animals and anatomy but never quite made concrete. By the end of the song, it feels pointless to try and capture “it” in language: Whatever “it” is, it’s closer to Regina’s laugh than any words in Portuguese or English can describe. Taxonomizing life with language, the moment seems to suggest, is uproariously vain. Even the music itself eludes capture, and sits in the space between—take, for example, the opening plinks of a deliciously desafinado piano, chirping like a thrush caught between keys.

Elis & Tom wasn’t an immediate success. The record reportedly sold only 40,000 copies in Brazil; after a few performances together, Regina and Jobim parted ways, Regina careening toward a cocaine habit, and Jobim toward a second marriage with a woman younger than Regina. In 1985, struggling to support his family, Jobim licensed the rights to “Águas de Março” to Coca-Cola for a six-month contract that happened to overlap with the “New Coke” fiasco. An advertiser’s job is far more literal than the artist’s, and the opportunity the admen saw in “Águas de Março” is obvious enough: The tune was catchy, international in an era when globalization was in vogue, yet malleable enough that, with some smoothing-down, it could become convincingly all-American. And the punchline was teed up. Never once in “Águas de Março” does Jobim flip the order of his “It is…” sentences to “...is it.” But for Coke, funneling this list of images towards one definitive and shiny declaration—Coke Is It!—was the commercial’s raison d’être.

While Coke was weathering backlash for changing its formula, Jobim faced censure among fellow artists for “selling Brazil to Coca-Cola.” It was hardly surprising that artists would be upset—the United States had legitimized the junta, and Coca-Cola was a globally recognized symbol of consumerism that artists internationally and at home in Rio regularly subverted for political critique. The ease with which Jobim’s composition slotted into American capitalist culture may have proved the suspicions of left-leaning Brazilian youth that bossa nova was a maddeningly apolitical artform, lacking the cultural urgency of MPB songs like Regina’s 1979 hit “O bêbado e a equilibrista,” a rallying cry for the re-democratization of Brazil. And what Jobim sold was larger than Brazil—he’d cashed in on the open-ended promise of “it,” scrubbing his collaged landscape of life so that Madison Avenue could redraw it in their image.

Can we forgive Jobim for needing the money? In an interview with the São Paulo magazine Veja, Jobim rejected the claim that he had sold out. He hadn’t sold anything; he had simply licensed the song for a six-month contract. Besides, he hadn’t walked away with millions. If he had, he would have bought back the rights to his own work—in a 1986 article in The Los Angeles Times, he admitted that “his naivete in dealing with music publishers cost him dearly.” “I would correct the lyrics, the harmonies, the melodies, and even the rhythm. I would do that so I could die in peace,” he said. “If I died right now, this minute, I’d leave behind an incredible trail of nonsense.” But an “incredible trail of nonsense” is just what money couldn’t buy. It’s the parting blessing Regina left behind on “Águas de Março,” a string of syllables as delightful and baptismal as late summer rain.

Special thanks to James Gavin for his article “Elis Regina: True Diamond,” and to Isabella Da Fonseca.