John Cale's live album comes at a time when he has rediscovered his passion, intensity and youthful energy. The seasoned singer talks to Kevin Courtney

This is a big year for John Cale. Besides being the 40th anniversary of the classic album, The Velvet Underground and Nico, it's also the year the Welsh-born avant-rocker and former member of the influential New York art-rock collective turns 65, which means that, should he desire to retire and live out his days back in his home town of Garnant in South Wales, he would qualify for a bus pass.

"That's right! That's right! And I'll be collecting, don't you mistake it!" he bellows in a rather unconvincing pensioner's quaver. "No way. I don't understand why that figure sticks out. Well, I do, it's because the government says it, but right now every government in the world wants you to keep working so they can get more taxes."

John Cale intends to keep on working right into his 80s, and it's not to feed the government's tax coffers - it's to feed his insatiable hunger for new ideas, new styles, new technology and new ways of doing the old rock 'n' roll thing.

"I don't know what a 65-year-old man is supposed to feel like anyway," he reflects. "I think your physical well-being dictates your mental well-being, and I'm feeling fine."

He's certainly in rude health, if the bull's roar on his new double-live CD, Circus, is anything to go by. The album spans Cale's 40-plus years in this business we call show, from his early, often ridiculously lengthy noodlings with avant-garde bandleader LaMonte Young in the early 1960s, through his time with the Velvets, and taking in a long and dizzyingly varied solo career that has spawned such classic albums as Paris 1919, Fear, Helen of Troy and Cale's collaboration with Lou Reed, Songs for Drella.

His music has gone from jazz to classical to dark post-punk to - most recently - hip-hop and funk, but always at the core is Cale's deep, stentorian Welsh burr, declaiming the lyrics with the authority of age, experience and an all-too-intimate acquaintance with the dark side.

Circus comes at a time of twilight resurgence for Cale, during which he has rediscovered his passion, intensity and youthful energy. It began with his superb 2003 album, Hobosapiens, Cale discovering the twin joys of hip-hop and Pro Tools, and continued with 2005's Blackacetate, an album that blended his classical, rock and experimentalism to startling, often challenging effect.

These two albums saw Cale refocusing on his solo work after a fragmented couple of decades, and finally finding a backing band that can fully realise his dauntingly eclectic back catalogue in a live setting.

THE TIME SEEMED right to capture Cale's live show, and harness the onstage power of this old rock 'n' roll beast. Many who might be wary of wandering into the tangled forest of Cale's canon might find Circus a fitting introduction to Cale's work, and an easy-to-follow map of his world.

The album begins with a drone, evoking Cale's early avant-garde work with LaMonte Young, and glides into the tribal beat and swooping viola of Venus in Furs, and thus begins the 40-year history of Cale's singular career. Femme Fatale and Venus in Furs cover the Velvets period, during with Cale wrestled with both Lou Reed and the band's mentor, Andy Warhol, for control, a battle eventually won by Reed when Warhol stepped out of the picture and Cale departed after the band's second album.

Hanky Panky Nohow, Save Us and The Ballad of Cable Hogue showcase his early solo work, when Cale was discovering that he could draw from rich musical roots while still being out-there and challenging. Style It Takes nods to his many collaborations, this one with Lou Reed on the pair's tribute to the Andy Warhol, Songs for Drella. Zen, Woman, Outta The Bag and Look Horizon cover his latter-day work, and show that his creative juices have far from dried up. And the lengthy centrepiece Gun revisits the anger mismanagement of the late 1970s, when Cale interspersed brilliant albums with onstage confrontation and offstage self-destruction.

"Every time we go on tour we always use one song as a base for an improvisation, and Gun is the one on this last tour. I don't do it the same way on this tour, but it is in the set, and one of the things about Gun especially is that you can't do it every night, it's one of those things that goes off into Miles Davis territory. I really feel sorry for the band, but they did so well on it, I'm really happy with the way they did it, and the song just changed focus entirely."

At least Cale's current band didn't have to witness the notorious chicken-beheading incident in the 1970s, when Cale ritually decapitated a dead chicken onstage, prompting the entire band to quit in protest. The idea of this arty Welshman as a kind of Ozzy Osbourne figure is hard to imagine, but, by his own admission, Cale was lost in his own heavy-metal hell. What does he think now, looking back on those lost years?

"They were dark at the time, but when I look back on them now, they were such stumbling curiosities. You know, you think you really know what you're doing, and you don't. And you look back and go, what an idiot. You thought you were saving time doing all that shit? Wrong. [ That's] when you realise all that time you've wasted. I've sort of been on a roll for the past three years. And when I think back on all the time that I've wasted, I think, what a waste. I mean, you think you're being efficient, and you're not.

"I think I still have some of the rage, but it's a different kind of rage now. I was in the control of the rage at the time, in the 1970s, I'm not quite that manic any more these days. I thought I had it under control, but when I look back on it, it was a very unnerving time for me personally. My personal home life was a disaster."

The 1980s and 1990s were a time of inconsistency, during which he worked on a confusing mix of side-projects and collaborations, sometimes striking a chord, but often hitting a creative dead-end.

He set the poems of his fellow Welshman, Dylan Thomas, to music on the song-cycle The Falklands Suite (the making of the record was chronicled in the film Words for the Dying), and he collaborated with Brian Eno on the 1990 album Wrong Way Up. Cale was already an accomplished producer, having worked on albums by the Stooges, Nico and Patti Smith, and in 1987 he produced the debut album by a bunch of drugged-out scallies called the Happy Mondays. (He is, as we speak, holed up in a studio in LA, producing the second album by New York art-rockers Ambulance Ltd.)

He took time from his patchy solo work to rejoin his old sparring partner in a short-lived reunion of the Velvet Underground. And he contributed tracks to various film soundtracks, including a version of Leonard Cohen's Hallelujah for the animated feature Shrek, which was replaced on the soundtrack album by a version by Rufus Wainwright.

Through it all, he never stopped playing live; this week he's in the Village in Dublin, his first appearance in Dublin with a full band. It will be a chance to see and hear up-close what's apparent on the Circus album: at 65, John Cale is still a force to be reckoned with.

THROUGHOUT CALE'S ECLECTIC pursuits and his dabbling in various genres, he has never lost sight of the rock 'n' roll dream that sits at the core of his being. It's there on the live album, on tracks such as Dirty Ass Rock 'n' Roll and a cover of Rufus Thomas's Walkin' the Dog, but it's most prominent on Cale's eerie interpretation of Elvis Presley's Heartbreak Hotel (the song he was performing when he chopped the chicken's head off).

"That's what I remember best from my childhood - the birth of rock," he recalls. "That's where the excitement came from. When I was working with LaMonte in avant-garde music, the fun factor was close to zero. After about two years of it, and working so hard on it, I just went, okay. The blues explosion was happening in New York, and I suddenly realised I missed out on my teenage years here, I have to do something."

Cale's teenage years were spent in Garnant, South Wales, where his father was a coalminer and his mother a teacher. His talent on the piano and viola earned the young Cale a place at Goldsmith's College in London, and a serendipitous meeting with US composer Aaron Copland led to a summer scholarship at Boston University. He then moved to New York, where he met up with a like-minded young rocker, Lou Reed, and the pair decided to form a band.

Forty years after the release of the seminal The Velvet Underground and Nico, Cale still hasn't lost his appetite for new ideas, new technology and new reasons to rock. He's a self-confessed "techno-slut", the first in the queue when a new gizmo or guitar pedal comes on the market, and he assimilates new musical styles with sponge-like efficiency.

His current studio heroes are Dr Dre and Pharrell Williams, and he's excited by the "ferocious grooves" on albums by Snoop Dogg and the Game. He's also captivated by the psychedelic experimentalism of fellow Welshmen Super Furry Animals, and was a guest musician on their album, Rings Around the World.

In a poignant scene in Words for The Dying, Cale makes a visit to Wales with his American wife, Rise, and his three-year-old daughter, Eden, returning to his home town of Garnant, in the industrial Amman Valley, and visiting his ageing mum at the local nursing home.

Nearly 20 years later, his mother has long since passed away, Cale has divorced from his wife, and Eden is a grown-up woman working in New York. But Cale's home country still evokes mixed emotions, and whenever he revisits Wales to play a concert, he feels its gravitational pull.

"Well, it's changing, Wales is changing like every other country. It's going through a different renaissance all the time. We did go back to visit, to play a gig in Cardiff, and I went by my old house. Every time I go back, the same kind of pull happens. It's spooky. As soon as you go past Cardiff, suddenly something happens, and it's probably got a lot to do with something from my childhood, when I would be travelling to Cardiff on the train, going home on a Saturday night."

Has Cale ever wondered what his life might have been if he hadn't left Wales all those years ago? "I don't think you'd be talking to me now. That place kind of spat me out."

Circus live is out on Feb 2 on EMI. John Cale plays the Village, Dublin, on Friday