“It felt like there were people representing different parts of music that we held in high respect,” the Band’s Robbie Robertson said recently in a press tour celebrating the run up to the 40th anniversary of his group’s classic concert film The Last Waltz. “Who’s going to represent the music of New Orleans? We’ve got to get Dr. John in here.”

But Robertson's goal wasn't to represent the music of New Orleans. He was aiming to represent the music of his era, the ‘60s, a time of innovation and self-realization and cross-pollination and deracinating appropriation, in the last moments of its waning light. “It felt like the end of an era,” Robertson said. “Something needed to be brought to a conclusion, in everything. Around the outskirts of what we were bringing to a conclusion, it felt like there was another kind of revolution stirring: Of hip-hop, and punk.”

So sure enough, early on in that classic rockumentary, Dr. John walks out onstage, foppish and pimpish in a beret and pink bowtie. Hirsute with a Cheshire grin, “The Doctor” squawks out a gratitude and and begins to tell of a starry tryst in his cajun accent. As the song comes to a conclusion, Dr. John, whose real name was Malcolm Rebennack, launches into an extended musical shtick: Tying together ending after ending after ending into a miniature suite of outros: cliche and familiar musical culminations anyone would recognize from the canon of American roots music. Then, it finally does end, dissipating in a gauzy billow of antebellum strings. He stands, glinting in a spangled coat, and bows to thunderous applause.

Growing up in New Orleans, Mac Rebennack naturally gravitated to music, and to Henry Byrd, the town’s legendary pianist. Byrd was an institution in New Orleans from the time Rebennack was born, and went by the name Professor Longhair. Rebennack remembers meeting Byrd, whom he idolized, and whose friends called him ‘Fess, as a kid: “I was also fascinated that he was sitting out there in a turtleneck shirt with a beautiful gold chain with a watch hangin' on it, and an Army fatigue cap on his head,” Rebennack remembered. “And I thought, ‘Wow, I never seen nobody dressed like this guy.’ Just everything about the man was totally hip. And he had gloves on him, too, beautiful silk gloves. I'll never forget this.”

He certainly didn’t. Rebennack sponged up the culture and identity of New Orleans and then took it to L.A., where he rolled it out for everyone from Frank Zappa to Sonny & Cher. He found an equation between the psychedelia of the late ‘60s with the voodoo mysticism of his hometown, and The Night Tripper was born: a cartoonish alloy of New Orleans culture and oddities, real and imagined. He could market it nicely too—he first went by Professor Bizarre, co-opting Longhair while exoticising him. But then he picked another honorific and another pseudonym, and became Dr. John. When the Band moved to L.A. to make their unimpeachable second album, everyone in the music scene knew Rebennack for his madcap stories of his hometown and his fabulous dress. So when, years later, the Band wanted a taste of the Bayou, that’s who they called.

About a year after The Last Waltz was filmed, but before it was released in 1978, Professor Longhair, who had never “crossed over” like Rebennack seemed to so easily, opened a club in New Orleans called Tipitina’s. The club was named after a song he wrote that was later added to the National Recording Registry for its cultural significance. That’s where Robbie Robertson finally got to meet Longhair, New Orleans’s most important jazz pianist after Jelly Roll Morton. None of Longhair’s recordings had made it far out of New Orleans in their time, so the opening of Tipitina’s, and its establishment as one of the city’s preeminent juke joints, helped get the word out.

Longhair recorded for almost three decades before any of his work was put together into an album, New Orleans Piano, 1972’s compilation of his singles made between 1949 and 1953. For three decades, he represented New Orleans’s odd musical amalgamation: creole, jazz, zydeco, soul, rumba, boogie-woogie, even when he was out of sight, or thought long dead. His music was carried by the city, in bars and clubs, because it celebrated its identity. His were sounds he picked up tap dancing on the street for snake oil salesmen, studying under Champion Jack Dupree and especially Tuts Washington, or sneaking into bars with a mustache drawn on to fake his age.

Even by New Orleans’s standards, Longhair’s piano playing was a hard-to-categorize mix. He learned boogie-woogie from watching local musicians’ hands, but when he played it himself he leaned further ahead on the beat so it sounded more like Latin music. No one really knew what to call it, other than New Orleans piano, which is what it was.

New Orleans Piano is bawdy and colorful, full of priapic metaphors like “Ball the Wall” and “She Walks Right In”. His band sets the roadhouse standard later aped by Nicky Hopkins and Bobby Keys on Exile on Main Street. But no instrument is more powerful in Byrd's combo, not even his multilingual fingers, than his voice. Every song sounds a bit like he’s hitting on someone from the bandstand, and just how he describes in “In The Night”—“In the wee wee hours between midnight and day.” Byrd’s randy, winking baritone, like a bassy Groucho Marx or Shock G’s grandfather, turns into yodels on “Tipitina” and “In The Night”—goofy, yes, but not shtick, or at least not for the purpose of getting on TV. “Hey Little Girl” and “Willie Mae” both rise from Longhair’s boiling gut and climb up to a raspy peak.

Longhair’s “Bald Head”, which isn’t on New Orleans Piano, had made it to #5 on Billboard’s R&B charts in 1950. But it did little for the man; that chart had been renamed the previous year, when it was called the “Race chart”. There was no money in it, and the only likelihood of commercial crossover belonged to white artists copping it. He got screwed on record deals too: by the ‘60s, he’d switched careers from pianist to professional card player. By the late ‘60s, Longhair had disappeared and was thought dead. A group of teenagers set out to find him in 1970, and did, where he sweeping up in a record shop. He hadn’t played the piano in years.

A new interest in cultural archivism gave birth to the New Orleans Jazz and Heritage Festival, and by 1971, Byrd was performing in front of thousands in his hometown. The world had changed dramatically during Byrd's chapter of hardship, and reemerging from it must have been a shock. In 1977, Paul McCartney hired ‘Fess to play a yacht party he was hosting; Byrd had no idea who McCartney was. He got to enjoy mounting fame and appreciation until his death of a heart attack in 1980. He was supposed to tour opening for the Clash that year, another kind of revolution.

Longhair hardly made it out of New Orleans himself. But thousands joined the second-line for his funeral. His “Go To The Mardi Gras” is a staple of the yearly carnival—“as common here as holiday carols.” He became New Orleans, even if he’d never be its emissary.

And yet: when Robbie Robertson wanted to represent New Orleans, he called Mac Rebennack. This isn’t bad, inherently. There’s nothing to suggest that Dr. John’s a fake, or an undeserving songwriter. But it was wrong, incorrect. Dr. John didn’t write the music New Orleans parades to all year long. He didn’t stir its manifold soul with styles that were new and old. He was its emissary, not its doctor. He still holds some association with our imagination of New Orleans’s music, maybe because he was chosen to represent its music at a moment and on a stage where its image in popular imagination was asserted.

See, that's because the culture of a place can't just be folded up like a tent once a generation's music becomes passé. At The Last Waltz, when the whole history of New Orleans's music was to be advertised, who was under the spotlight? And who got to make that choice? Maybe Rebennack got called up when someone else deserved to. The tragedy is that person was back in New Orleans for just a little while longer. But the miracle is that he'll be there forever, too. Don't expect him to come represent itself. Go to the Mardi Gras.

—Charlie Kaplan