They're playing venues across the UK, including Birmingham's O2 Academy on Thursday, to bring a mix of songs and verse to fans.
Neither is showing any signs of slowing down and neither has any intention of retiring.
Dr John keeps it real on the road and avoids living it up. "I've got a driver. Well, a hire car. The nearest I get to a limo. I get a few requests from the audience, but I carry on regardless. I'm writing more than ever these days. The more you write, the more you write."
He celebrated his 65th birthday two years ago but didn't go wild. "I had a meal out with the family. Thing is, I still can't imagine life without me being in it. I'm maybe a bit more health conscious than I have been in the past. But it doesn't involve a regime of any kind, I don't visit any gymnasia, I don't eat rubbish but I never did. I don't have any lifestyle advice."
Dr John originated from Salford, in Lancashire, but moved to Essex more than 20 years ago. "It is the longest I have lived in any county. I feel like an Essex bloke. I don't watch Towie mind. I haven't watched any soaps since Dallas finished, unless you count the Sopranos. I was more than proud when they used my poem Evidently Chickentown at the close of that penultimate episode."
Rather than looking back, Dr John continues to look forward. And that's helping him to be happier than ever. "I am but I don't like to analyse it too much. You know the only way is down."
Cornwell, who is the same age as Dr John, is happy with a career that has included successful work with The Stranglers and a rewarding solo career, including last year's album, The Rise And Fall Of Hugh Cornwell.
He's always thought of himself as being an outsider. "I love the idea of a black sheep – maybe because I identify with it. People can't stand being alone and I wonder why that is. I've tried cohabiting, but it doesn't suit me because I like my time alone to think. I think that's why garden sheds started."