It's also much the same as the sense of longing that sits at the soul of other great gospel and blues singers, from Elvis Presley to Bono and Tori Amos. As such, it seems fitting that the two latter singers are included on Tower of Song, alongside the likes of Sting and the Chieftains, Trisha Yearwood, Elton John. But it's the Irish connection that really gives Lenny a kick. He, after all, is the man who, when he first performed here in 1972, said: "I've waited all my life to sing this song in Ireland," as a preface to Kevin Barry. He also recited Yeats that night, has frequently spoken of his affinity with Joyce and uses black humour à la Beckett, even if many miss this dimension in his music. Speaking now, on a phone line from his Zen retreat in California, at 7.30 in the morning, his time, he elaborates on these associations.

"I never really thought of it as Irish art, just realised there was a bunch of writers coming out of that curious place called Ireland and they really had a handle on the language of the heart that I respond to, especially Irish songs," he says.

"Early in life, you do find certain voices that really speak to, nourish and guide you. And for me, many of those voices were Irish, like Joyce. Not just the entire work, or the fact of the total commitment of the man to his enterprise, but certain paragraphs, sentences, rhythms like: 'snow is general all over Ireland'. Just that sentence coming at the end of The Dead really connected with me, though why, I don't know. Maybe because my nanny was Irish!"

Maybe, but Cohen's family was Jewish. So does he buy into Neil Sedaka's claim that "the oppressed cry at the heart of Jewish music" is also central to Irish music/art, or the suggestion that the impetus behind his own art is a desire to burst beyond religious/political oppression?

"I don't think any of us starts with a strategy," he suggests. "You start with some kind of urgency that is indistinct, and it takes a lifetime to uncover what the thrust of your activity was about. You sing from a kind of thorn in your side, which may just be the human heart aching in its particular predicament. And all art is an effort to address that aching. Not just Jewish or Irish art, though both do seem to be more strongly rooted in a verbal tradition, rather than a visual. The Irish ache volubly and it's all there, in your words and music. That's also true of Jewish people."

In this context, couldn't one legitimately argue that The Chieftains and Sting kill the original prayer at the soul of Sisters of Mercy by turning the song into a jig?

"No! I like what they did because now the song sounds like it's been there for a couple of hundred years!" says Cohen. "They bypass the association of the song with me, take it as a song that exists in the world, that you can do anything with, because there is something strong and true about it. In that sense, you don't have to treat it reverently, or get behind the narrative. It's a good tune and I love the fact that it's now an Irish jig!"

Really? But surely Sting's claim that he took his lead from the fact that the song was set in a bordello, is far from true to the original text, where the narrator sings: "We weren't lovers like that / And besides, it would still be alright?"

"Well, some people say everything is set in a bordello!" Cohen retorts, clearly able to live with this form of violation - as long as the publishing royalties keep rolling in, no doubt. And while we're on the subject of sex 'n' spirituality in Cohen's work, he recently suggested that "real spirituality has its feet in the mud and its heart in heaven". Does he believe that Bono captures this duality as he drips all over his jazz deconstructionist interpretation of Hallelujah?

"Drips?" he replies, laughing. "You said that. But wait a minute I gotta get another cup of coffee, this is getting serious! What do you mean 'drips'?"

As in sexually, Leonard. As though Bono is trying to place his base, carnal longings within the context of religious yearning; particularly after seeing a naked woman bathing on the roof, to paraphrase the lyric.

"If so, he's right up my alley! And David's alley!" says Cohen, wholeheartedly agreeing with Bono's "quite beautiful" observation that David (as in the Bible) probably was "the first, great blues singer" and adding "Bono is a very smart guy". However, Lenny almost retracts this commendation as soon as it's pointed out that Bono gets the lyric wrong in Hallelujah, substituting the word 'lips' for 'tongue', thus destroying the internal rhyme in the line, 'nothing on my tongue, but Hallelujah.'

"He did!" exclaims Cohen. "Jesus Christ" I'm going to have to listen to that thing again! He's had it, he's out! So I sing, what? 'Nothing on my tongue'? And he sings 'nothing on my lips'? He's ruined it! He's dead. Curtains!"

Cohen may sound like he's joking, but he has previously explained it sometimes takes him up to five years to write a song because "you shatter versions of the self until you get down to a line, a word, that you can defend, that you can wrap your voice around without choking." Happily, Aaron Neville requested in advance that Cohen himself replace the "I need to see you naked" line in Ain't No Cure For Love.

["The] song will get played' if I sing that line," he explains. "And he has other considerations that are subtle, racial, so I had no problem with that. And I really cherish Aaron's respect for my work. He has a baroque approach to singing, something that is completely underestimated, in terms of the elaborations he uses, which are Eastern. He's brought that aspect of his music to an incredible level of refinement."

One could say much the same about the voice of Leonard Cohen, which is probably best appreciated when viewed within the tradition of European art music, particularly speech-song; though, clearly, listeners more besotted by classical models of singing claim he's one of the worst singers in the world. Not so Aaron Neville, who told this writer that Cohen is "a beautiful singer" because of the "emotional power" in his voice, a quote Cohen hadn't heard. He pauses before responding, then says, as dry as ever: "I've stopped hoping that people will praise my voice, though, obviously, I've a couple of friends out there who like the way I sing."

Quite. And despite once aligning himself with those who say "we may be ugly / But we have the music" Cohen has also, obviously, had more than his share of lovers who regard the man himself as beautiful, with a positively potent sex appeal not least in his voice. Indeed, in 1987 he was voted one of the 10 Sexiest Men in Canada by Chaterline. His most recently published romance was with Rebecca De Mornay, to whom Cohen dedicated his last album The future. So, is that now the past?

"Yeah, she got wise to me and left!" he says, halting all incursions into his private life, as usual. But what about reports of him relatively recently cruising the streets of L.A. looking for a "sweet companion". Surely that form of aching eases when one passes 60, as Cohen did last year?

"That aching is not supposed to ease" he claims. "My old teacher said, 'the older you get, the lonelier you become and the deeper the love you need' and that's true. You can have that ache, even if your sweet companion is sitting beside you in the car. But I was never working to master my loneliness, in that sense. I wanted to liberate it, to ravage the land. Now I can embrace everything with my loneliness."

Does this mean Cohen still lives according to the code crystallised in his lines: 'Life is filled with many sweet companions / Many satisfied one-night-stands?' Likewise, is he still driven by the notion that his art is imperiled by permanence; an ideological tendency that dominates his poetry, novels and songs and is similarly epitomised by the fact that he himself has left behind "everything you cannot control" - as in his parents, wife, son, daughter, numberless lovers?

"That's a stupid idea, though it is what I lived," he says. "But, life is filled with many sweet companions, many one night stands, in the sense that it is impermanent, fragile and you can't really lean on anything too heavily. Yet, I've always said I don't know where the novels, poems, songs come from. If I did, I'd go there more often. But I do think that human compassion is defined by the ability to raise your voice in song, to alter the landscape, affirm some kind of connection with something beyond your body, mind, and the frailty of the whole dismal situation."

Does seeking this connection mean that, in essence, Cohen is singing to God? With nothing on his tongue but Hallelujah?

"You could put it that way, but - though this may be blasphemy - it transcends God as we might imagine we know God, transcends theology. In the end, it really is about love and about affirming the existence of love."

Looking beyond the end, in the song Lover, Lover, Lover, Leonard Cohen cries out that were he to start again he'd ask his father for "a spirit that is calm". But would he, finally, if a spirit free from longing meant there would be no poetry, no songs?

"A prayer is something that is continuous. You can't claim these things," he suggests. "It's like when the children of Israel were given manna, they couldn't store it. They were given enough for each day and if they tried to store it, it would go rotten at night. Our lives are like that. You've got to renew the prayer. Yet I don't know that there would be no songs, if there was no longing. And, like I say in the song Light as the Breeze, maybe the most we can reach for are those times when, 'like a blessing come from heaven / For something like a second' we are cured and our hearts are at ease."