John Otway harshly describes himself as ‘rock’s greatest failure’. And with little commercial success after 48 years in the business, some might unkindly agree.

He does, however, have two hits to his name, and is now celebrating as the first of them has hit the age of 40.

It is four decades since the eccentric punk-rocker scored a Number 27 hit with Really Free in 1977, and he is marking the occasion with a show marking the anniversary at The Bullingdon, in Oxford’s Cowley Road.

It coincides with another milestone. This year he hit 65, the occasion prompting yet another tour, titled, of course, Cor Baby...I’m an OAP!

“I always intended to get a proper job,” he says. “But instead I’ve become an OAP on the 40th anniversary of my hit, which is a double milestone.

“I’m 65, still leaping off the same step ladder – and still getting away with it!” he laughs. “I’m not surprised to have got this far though; this is what I had always planned!”

Few people have based such a convincing career – and garnered such a cult following – on such flimsy success. While the hit reached a modest 27, it took him another 25 years to get another – his song Bunsen Burner.

The single, featuring music sampled from the Trammps Disco Inferno and lyrics written to help his daughter with her chemistry homework – reached number nine in 2002 after a campaign by fans who had vowed to get him a second hit for his 50th birthday.

“I’m very proud of my hits,” he says. “Especially the first. I couldn’t have called myself a rock star had I not had a hit. Before it I was a struggling artist but after it I was a star. And I’ve had friends who haven’t had any hits.”

So, looking back at those heady days of fame – and hair – did he feel surprised at his chart success? “I am less surprised it charted than I am surprised that all the others were flops,” he says. “I expected them all to be hits. I’ve been surprised 38 times.”

Bunsen Burner – which featured 900 fans on backing vocals – did assure his status as a star at least. “I had quite liked the idea of being a one hit wonder,” he says. “But a two hit wonder is definitely better. My fans helped me get the letter ‘s’ on the right side of the word ‘hit’.”

Still, he embraces the idea of failure. “I find it surprisingly fitting,” he says. “Hearing someone crowing about their success is nowhere near as entertaining as hearing about the banana skins I’ve encountered.”

Not that he hasn’t been busy since. He comes armed with a new album under his belt, recorded in the playground of many a rich and famous pop star – Montserrat.

Well, make that former playground.

Though it was used by everyone from Dire Straits and Status Quo to Elton John and The Police, no one of note had recorded on the paradise isle since the Rolling Stones in 1989.

Since then it has been devastated by storms and a huge volcanic eruption, which sent most of the population packing.

“They’d had a hurricane and a volcano so I thought we’d be the third natural disaster,” he laughs.

It was funded by a ‘kickstarter’ appeal launched at one of his regular haunts, Oxford’s Bear pub – at which he performs every May Morning.

He reached almost £35,000 – enough to get him and a band and his long-suffering roadie David ‘Deadly’ Crabtree, from Eynsham, out to Montserrat, and to book producer Chris Birkitt – best know for Sinéad O’Connor’s Nothing Compares 2 U.

They stayed at Beatles producer George Martin’s old place – another ambition for Otway. And because the island’s famous bolthole, Air Studios, had fallen into dereliction, he created a new studio in the basement.

When he’d finished, he donated much of his musical equipment to the islanders and future visitors to help sustain the live tradition of music.

“It was brilliant,” he says. “We found out when the height of the hurricane season was, which was September 12, and went there then.

“We knew we’d be making a lot of noise and didn’t want to disturb anyone.

“In the event, there were no hurricanes, though we still left our own trail of destruction. We had a lot of beers. There are only 5,000 people left on the island, which is about the size of a nice English village, and there were 50 of us – which is one per cent of the population – and we drank the island out of beer.”

And the resulting album? “It’s a great album – rocky with a couple of ballads,” he says.

Sunday’s show will see him joined by Deadly – who got his name through his footballing prowess and is the butt of many of John’s jokes (though the banter goes both ways).

“However big a rock star you are – even if you’ve been to Montserrat and had a couple of hits – it’s important to look after your roadie,” John laughs. “They are more important than a lead guitarist; after all, you can always replace them. A good roadie is hard to find and Deadly is a good one. He’s lasted longer than any of the others I’ve had. He’s also the only one not to have been hospitalised.”

Hailing from Aylesbury, Otway’s career took off during his residency at Oxford’s former Oranges and Lemons pub (now the Angel and Greyhound) in St Clement’s.

“It started in Oxford in 1976 and ’77,” he says. “The Beatles had the Star Club in Hamburg, and we had the Oranges and Lemons, where we learned our craft. I did a whole year there playing every week.”

And while his career bumped along with a succession of flops, his fans stayed loyal, following him to watch his dynamic, and occasionally dangerous, stage shows, enlivened by stage dives from speaker stacks and somersaults from his trusty step ladder – which remains a prop to this day.

In 1998, 4,000 people packed the Royal Albert Hall for a show which featured Otway’s first musical outlet, the Aylesbury Youth Orchestra.Fans at The Bullingdon can expect the same knockabout humour and punk-fuelled pop which sustains him through 150 gigs a year.

So, as he celebrates this momentous occasion, does he have any regrets?

“My main regret is my lack of hair,” he says. “I tried to grow it back over the past few years but people say I look too much like the child catcher off Chitty Chitty Bang Bang.”

And then there’s Deadly.

“He’s a roadie but he takes more glory than me,” he complains. “He does have a wonderful sense of comic timing but that makes him go down even better than I do. And he generates sympathy.

“The terrible thing is he gets the girls; far more girls are attracted to Deadly than me. I always end up surrounded by blokes, so I end up having a go at him even more – but that only accentuates his success. It’s a vicious circle.”

But, he insists, there is more chart success to come.

“The new album features 11 tracks in all, 10 of which are definitely hits!” he laughs.

“If not, and judging by the 25 years it took to get my second hit, I’ll be 75 by the time the next comes around.”

* John Otway plays The Bullingdon, Oxford, on Sunday. Tickets from wegottickets.com