How is there not a biopic about the life of Mac Rebennack, the New Orleans native who rebranded himself Dr. John and devoted his career to keeping alive the traditions of his hometown’s interconnected voodoo and musical cultures? On the way to becoming Dr. John, he dropped out of Catholic school, got hooked on heroin, and did hard time in prison.

Today, he’s an honest-to-goodness doctor, thanks to an honorary degree from Tulane University. In between dropout and doctorate, he backed Frank Zappa, jammed with Eric Clapton and the Rolling Stones, and laid down the theme song to the ’90s sitcom, Blossom (Remember? “And in my opinionation, the sun is gonna surely shine.”)

And don’t forget that he’s the inspiration behind the Muppets’ Dr. Teeth, or that the Bonnaroo Music and Arts Festival is named after his 1974 album, Desitively Bonnaroo, or that he’s the voice behind the original Popeye’s “Love That Chicken” jingle.

A Dr. John biopic is an Academy Award begging to happen. But, Rebennack claims a film project has never even been suggested to him. “No, nobody’s come to me with an idea about that,” he reports, on the phone while riding the long bridge across Lake Pontchartrain. “I have a good belief system that everything that’s good works and can be a blessing.”

For a 75-year-old man with a lifetime of stories, Rebennack maintains a cool, slow-talking demeanor, offering brief but poignant answers to typical music reporter questions.

Is he bummed to miss Mardi Gras in New Orleans while he tours the Southeast over the first two weeks of February? “You gotta roll with whatever it is, you know?” Rebennack answers. “I’m gonna be wherever I’m gonna be. I’m flying off to Washington tomorrow, I think. And that’s life.”

Will his setlist draw heavily from his latest release, the 2014 tribute to Louis Armstrong, Ske-Dat-De-Dat, or is he still pulling from his autobiographical 2012 album of original songs, Locked Down, produced by the Black Keys’ Dan Auerbach? “I’m thinking it’ll be all over the place,” he replies. “I just was thinking about doing a tribute to Fats Waller. It’s my privilege to be able to do that.”

How’s he coping with the November passing of his longtime collaborator, Allen Toussaint, a friendship that dated back to their youth? “His son Reggie has been calling me in on every [tribute performance] to do with Allen,” says Rebennack, before adding, “My grandson passed too. His name was Allen. He was named after [Toussaint].”

The interview continues in that fashion — a string of surprising but abbreviated remarks. On putting together his current five-piece band (including drums, bass, guitar, and musical director Sarah Morrow on backing vocals and trombone), he simply explains, “I basically knew all of these guys from different things, you know? And that’s a good thing.”

But of all the topics we briefly discuss, the one that gets Rebennack truly animated is a mention of his old friend, Bunky Odom, the former right-hand-man to Phil Walden, who founded Capricorn Records and launched the Allman Brothers Band. Odom, who lives on Sullivan’s Island, helped to manage Dr. John in the early ’70s, and afterward accompanied him on tour, including on a trip to Europe.

“Bunky, yeah,” Rebennack exclaims, drawing out the “yeah.” “He was my partner. We ran together for a gang and a half of years.”

Odom remembers that “gang and a half” well, from his first flight into New Orleans and their first plate of crawfish together — Rebennack ordered seven pounds for himself, Odom claims. Likewise, Odom recalls how before shows, they’d roll two joints — one for the crew to pass around and one for Rebennack to smoke on his own. “He ain’t gonna pass it,” says Odom.

For all the stress that traveling with Dr. John may have caused him (Odom was responsible for doling out Rebennack’s daily dose of methadone — he didn’t fully kick his heroin habit until 1989), Odom remembers with excitement the joy that Rebennack created when he sat down at the piano each night.

“He called it radiating the 88,” says Odom, adding that if they got to a club where the piano was out of tune or broken, Rebennack would say, “I’ll play the half that works.”

“It wasn’t like it is today,” Odom says. “It didn’t have to be perfect.”

But in his free-wheeling but singular focus on radiating music, Dr. John has created perfection. From the gris-gris and ornaments that adorn his cane to the confidence and strength with which he launches into “I Walk on Guilded Splinters” or “Right Place Wrong Time” — even after three-quarters of a century on Earth — Rebennack has created a legacy that’s as iconic and fascinating as the life story of any American, ever. And the should-be movie continues in motion — he’s still living out the script today.