Dan Auerbach and Dr John: When Dan called the good Doctor Yet, apart from left-field hits such as 1973"s Right Place, Wrong Time, Dr John never converted his connections into sales. Now Dan Auerbach has become his latest disciple, and together they have made Locked Down, a terrific collaborative album which has already begun to reinvigorate the legendary piano-player's career. When I meet them backstage at the Howard Gilman Opera House in Brooklyn, at first sight they appear to be so much like chalk and cheese that one wonders how on earth they can have bridged that gulf to work together. Auerbach, 32, is dressed down, trim of hair and beard, and seemingly rather introverted. Dr John, meanwhile, at 71, sports an electric-blue suit, vaguely matching alligator-skin cowboy boots, a pale orange shirt, and braces gaudily patterned with cartoon street scenes. His autobiography, Under a Hoodoo Moon, reveals a life misspent as a desperate heroin addict; in an argument after a gig in the early 1960s, the ring finger of his left hand was famously all but shot off - you can see the Z-shaped remnants of it among his rings and bracelets. "We actually had a lot of common ground," says Auerbach, when asked what bonded them. We've both been playing music since we were little kids. That's the common language. It's not like he speaks French, and I speak German, you know? In fact, Dr John, a veteran of the mid-1950s New Orleans black R&B scene (real name: Mac Rebennack), talks in a hippified breed of jive that can border on the incomprehensible. The two first got together when Auerbach approached Rebennack to perform on a line-up he was curating at Tennessee's Bonnaroo festival. Rebennack says that his granddaughter duly furnished him with a copy of the Black Keys" breakthrough album, Brothers, and he was surprised to find that he liked it. "Dan's got great understanding," he says, "like, old-school understanding, in a young body." After Auerbach floated the idea of recording together, he visited Rebennack in New Orleans for a few days, bringing along a stack of "weird soul 45s, and Seventies Ethiopian funk." For hours, they listened and talked. Suitably impressed, Rebennack accepted Auerbach's invitation to come up to his Easy Eye studio in Nashville for a session. Though always an in-demand live performer, Rebennack had lost his way creatively. "See, they got a word - complacency," he reasons, pronouncing it "koh-play-sussy." When you get that , you ain't gonna do nothin. Dan pushed me into a zone where I couldn't get it, and that's the perfect place to be, to play music. "It was really apparent to me that Mac still has a whole lot of enthusiasm for what he does," says Auerbach. I just wanted him to make a record he could be really proud of. I didn't want to recreate anything, just to do something fresh, but informed by those old records of Mac's that I love. His game plan was to take Rebennack out of his comfort zone, sidelining the band, with whom he has cut some rather tepid albums in latter years, in favour of a whip-smart young combo assembled by Auerbach himself. This included the bassist and keyboard player from The Black Keys" old touring band and a drummer from Munich who specialises in the African polyrhythms which underscore New Orleans music. The great Dr John, globally renowned for his boogie-woogie piano playing, was duly presented with an arcane Farfisa organ, whose sound was another defining feature of those 1970s Ethiopian funk 45s. Auerbach also urged Rebennack to abandon his trusted method of turning up with pre-written songs, and instead to put his faith in "everybody brainstorming on the spot" - not by jamming together but in what Rebennack calls "a real group manoeuvre," collectively composing the kind of tight, punchy, melodically direct songs which have become Auerbach's world-beating trademark. They wrapped the whole thing up in 16 days flat, with Rebennack dropping his familiar banter to write lyrics of rare intimacy, apologising to lost loves, and to his disparate children and grandchildren for his absenteeism. Watching the two in conversation, it's clear that this was a collaboration with a rare spark to it. Auerbach appears humbled when Rebennack remembers a 1950s session he participated in with the R&B singer Joe Tex, which had a similar electricity. "Every now and then, you feel something," he concludes, sagely. Y'know, there's special things that happens in life. Rebennack, who has been entirely sober since 1989, has seen everything that a musician's life can offer. For Auerbach, it has obviously been a tonic to encounter this wizened, spiritually inclined veteran at such a vertiginous point in his career. "The thing we hated when we started out with the Black Keys," Auerbach reflects, "was that we didn't have immediate success, and we saw all these bands on big stages, and getting on the covers of magazines, and we were just roughing it, you know? Even though we're on the big stage now, and on the covers of magazines, we're just normal people. There's nothing I hate worse than a rock star. That kind of posing, I don't find it inspiring. That night at the Howard Gilman Opera House, it's very much Dr John who takes centre-stage, showcasing the Locked Down ensemble, who spirit up the album's funkiest highlights, alongside such rarely dusted-off gems as 1968"s I Walk on Gilded Splinters. Auerbach, post-millennial rock's stealthiest superhero, very mutedly fronts the combo, blasting off the odd guitar solo but also occasionally simply tapping a tambourine or scratching away on an Afro-percussion gizmo called the cabasa. Backed by this young band with fire in their eyes, the good doctor appears genuinely inspired. In America, first-week sales of Locked Down have already exceeded anything Dr John has released in 15 years or more. Does that make the man himself feel good? "Hey, of course," he purrs, "but you know the main issue? I feel good about the music. If that didn't feel good, an" it sold eleventeen kajillion records, it wouldn't matter. It's the music," he summarises, with a rattle of his bracelets, "that matters." Locked Down" is out now on Nonesuch