Leonard Cohen, Brighton Centre, Brighton, Nov 28

When Leonard Cohen steps on to the stage of the Brighton Centre tonight, he will begin the penultimate gig of a summer/autumn tour – his first in 15 years – that has seen him play 84 concerts in 20 countries including Poland, Spain, Greece and his native Canada.

This may not seem particularly remarkable in itself, but you need to add one important detail: the legendary singer and poet is now 74 years old, having celebrated his birthday in Bucharest on September 21 with a triumphant three-hour show in front of 10,000 fans.

Ageing is a phenomenon Cohen faced up to a long time ago. “Now my friends have gone and my hair is grey,” he sings wryly on Tower Of Song, released in 1988. “I ache in the places where I used to play.”

Cohen was 60 when he last toured in 1993 to support his album The Future, after which he apparently decided to retire from the rigours of the road, if not from making records.

He was perhaps satisfied with the work he had done to promote the music career he began in 1967 with his debut album, Songs Of Leonard Cohen.

Even then, at 32, he was older than his contemporaries in the American singer/songwriter movement, and when he touted his first songs – including classics-in-waiting such as Suzanne and Sisters Of Mercy – to the agents of New York, they would respond: “Aren’t you a little old for this game?”

But if Cohen imagined he would never tour again, circumstances were to conspire against him.

In 1994, continuing a long-held commitment to Zen Buddhism which he observes in parallel to the Judaism of his family name (“I’m not looking for a new religion, I’m happy with the old one”) Cohen made one of his periodic retreats to the monastary of his teacher Kyozan Joshu Sasaki Roshi, at the top of Mount Baldy in California.

There he acted as his master’s personal servant, rising at 3am every morning and making his breakfast.

Ordained as a monk and given the name Jikan, “Silent One”, Cohen remained at the Zen centre for five years, withdrawn from the world if not from the desires he articulates so powerfully in his songs.

“I shaved my head/I put on robes/I sleep in the corner of a cabin/sixty-five hundred feet up a mountain/It’s dismal here/The only thing I don’t need/is a comb”, he writes in his poem The Lovesick Monk, from his recently published collection The Book Of Longing.

Although he came down from Mount Baldy and released the album Ten New Songs in 2001 followed by the Dear Heather LP in 2004, Cohen could have continued largely out of the public eye were it not for the distinctly dodgy developments in his personal finances that occurred during his seclusion.

When his long-term manager and attorney Marty Marchat died in 1988, Cohen had allowed his affairs to be transferred to Marchat’s then-assistant, Kelley Lynch. There was a great trust between Cohen and Lynch and the two were briefly lovers.

“We were very, very close friends,” Cohen says. “I liked her immensely. Our families were close – she was helpful when I was raising my daughter.”

It was a friend of Cohen’s daughter Lorca who, in 2004, first indicated that her father’s retirement fund might not have been maintained in the way he would have expected. When Cohen investigated beyond his ostensibly healthy monthly financial reports he discovered that, of the $5m he believed he had saved, only $150,000 remained. Lynch had, it seemed, syphoned off her boss’s entire fortune while he was sitting in meditation.

“I paid attention to everything except the possibility my closest associate would embrace any irregularities in the discharge of her duties,” Cohen says.

Where others would have reacted with anger, Cohen’s response was philosophical and compassionate.

He tried to avoid legal action. “I didn’t really experience it as betrayal,” he says. “I’m not saying it’s bad; I have enough of an understanding of the way the world works to understand that these things happen.”

But Cohen was unable to avert the pain and embarrassment of litigation when it became obvious that, without recourse to the courts, he would remain responsible for vast sums in taxation on money he no longer had.

He eventually won a $7.5m claim against his former manager, but Lynch remains unwilling or unable to pay anything back to her ex-employer and Cohen was left with no alternative but a feverish return to work. “I said, ‘Let me start again,” he says. ‘Let me start fresh at 70. I can cobble together a little nest egg again.’”

And so Cohen began to plan the apparently never-ending tour he has now embarked upon, which, after finishing in Manchester on Sunday, is scheduled to resume again in the new year with a set of dates in Australia and New Zealand.

The response from the singer and his audiences has been remarkable. If the circumstances leading Cohen back to live performance were borne of necessity, he has embraced them with joy and the reaction of the critics, as well as his fans, has been ecstatic.

Reviews refer to the skip in Cohen’s step as he moves around the stage, his dapper, Fedoradoffing humility between songs and the euphoric, spiritual atmosphere generated by crowds who thought they would never see Cohen perform again.

Younger fans, many introduced to Cohen through Jeff Buckley’s cover version of his 1984 song Hallelujah, marvel at the power of the original singer in forum posts across the internet.

Even Prince Charles emerged as a Cohen devotee in the course of a 2006 interview with Ant and Dec, recommending the singer’s music to his sons.

“Is he a jazz player?” William asks his father.

“He’s a wonderful chap,” the heir to the throne replies. “He’s remarkable. The orchestration is fantastic and the words, the lyrics and everything.

He is a remarkable man and he has this incredibly laid-back, gravelly voice.”

Cohen’s voice is not exempt from his own droll lyrical reflections. “I was born with the gift of a golden voice” runs another line from Tower Of Song, which raises ripples of respectful amusement from his audiences whenever he sings it.

The low baritone is another dimension to Cohen which, like his famous melancholia, has improved with age to become an instrument of profound gravitas that lifts rather than depresses the spirit.

The slightly strained reediness evident in his recording of Bird On A Wire on 1969’s Songs From Room had, by the time of The Future’s release, been soaked in decades of red wine and cigarettes to become a Biblical rumble evocative of Cohen’s Rabbinical heritage.

These deep tones, perfectly suited to The Future’s hymn-like songs such as Anthem (which took him ten years to complete to his satisfaction) won Cohen Canada’s Juno Award for Best Male Vocalist in 1992.

“Only in Canada,” he joked in his acceptance speech, “could I win a best vocalist award.”

Perhaps the greatest tribute Cohen has received, though, is the endorsement of the many artists who have recorded versions of his songs.

Cohen is one of the most covered artists of all time.

Right from the outset of his musical career, when Judy Collins recorded a version of Suzanne that helped launch him as a songwriter, his carefully-crafted compositions have revealed their strength and beauty in the hands and voices of others.

More than 1,500 versions of his songs have been recorded by artists as diverse as Johnny Cash (Bird On A Wire), The Jesus And Mary Chain (Tower Of Song), REM (First We Take Manhattan) and Roy Buchanan (The Story Of Isaac). There are 95 versions of Hallelujah available to download from the iTunes Music Store alone.

Nick Cave, one of Cohen’s obvious admirers, led a tribute concert to the singer at the Brighton Dome Concert Hall in 2004, which also featured Jarvis Cocker, Beth Orton and Rufus Wainwright.

A similar event in Australia was filmed and forms the basis of the 2006 documentary I’m Your Man, which also features an emotional performance of Tonight Will Be Fine by Teddy Thompson and excruciating contributions from Bono and The Edge of U2.

As he now finds some of his greatest success in his twilight years, it is worth remembering that Cohen has not been consistently popular. Unfairly characterised in the 1970s as the epitome of the miserable musician beloved of angst-ridden, bedsit-bound young men, Cohen has had to accept his position in the public’s imagination, together with the bouts of depression that gave rise to it.

In America in particular, Cohen found his career in decline throughout the 1980s, and depended on his European audiences to keep afloat. “I know something’s gotten into the computer under my name,” he said in 1988, shortly after Jennifer Warnes’ album of Cohen covers, Famous Blue Raincoat, began his popular revival. “Every time they press the button out comes ‘gloom’, ‘despair’, ‘depression’, ‘melancholy’. They used to say razor blades should be distributed with my records.”

Cohen was never likely to compromise under these conditions, remaining, as a true poet, faithful to his muse and his audience, however big or small.

“Everybody lives the life of the heart, and we all know what it’s like to feel and break down, and I think we cherish that in our musicians and singers when they reveal that,” he said in 1993.

The lifting of his mood – which he attributes to a physiological effect of ageing – has accompanied, if not been caused by, the upturn in his popularity.

“A big part of my life has been about overcoming depression,” he says. “My time on Mount Baldy was one of the remedies.

“From the letters I receive, I understand that many people who are or have been in the same situation have felt a kind of relief, a healing while listening to my songs. This is something I have been very thankful for. But I don’t imagine that I am a therapist nor possess wisdom about what it is all about.

“I have described it as well as I could.”