Leonard Cohen occupies a unique position in music, and has the rare distinction of having never been imitated.

British rock writer Nigel Williamson, considering the career of Leonard Cohen, recently observed, "We often describe singer-songwriters as being 'Dylanesque', a band with great harmonies you might describe as 'Beatlesque'.

"But have you ever heard the word 'Cohenesque'? It doesn't exist, and that says it all. He's a unique artist and not only has he never been copied, I don't think anybody has even contemplated trying to do so."

Leonard Cohen - 75 next month and touring here again in late October/early November - occupies a unique position in music: he has been included in rock culture, but was never part of it. And although nominally a "folk musician" early on, he wasn't part of the folk movement either.

Cohen has always been a man apart: a writer with four acclaimed books of poetry and two novels behind him before his debut album Songs of Leonard Cohen appeared.

That album was released at the end of 1967. Others with debuts that year included Jimi Hendrix and the Doors. The multi-coloured air was infused with incense, marijuana and psychedelic drugs (the Beatles' Sgt Pepper's was released in June) and Cohen's monochrome Songs arrived with spare, poetic lyrics and a sense of quiet.

Susanne, Sisters of Mercy and So Long Marianne made people stop and listen. They were folk - but not folk of the protest movement of a few years previous, or the surreal lyricism of Bob Dylan.

Cohen - Jewish, from French-speaking Montreal - came from a more European consciousness. But most rock listeners were unfamiliar with French singers like Jacques Brel or Spanish poet Federico Garcia Lorca, his formative influences.

Throughout his long career - made more alluring when he retired to the Mt Baldy Zen Center monastery in California for a five year-stretch until 1999 - Cohen had outsider status, and that placed his music beyond the whims of cultural change. Bird on a Wire from 1969 resonates as much today as it did then, and his interpretation of The Partisan from the same year perhaps even more so in these troubled times.

Two years ago Cohen returned to the stage after a 15-year absence. His subsequent tours have been critically acclaimed and those seduced by his exceptional Vector Arena or Wellington concerts in January 2009 will doubtless have the Live in London DVD released last year.

But for anyone wanting an overview of the original songs which made people catch their breath, Cohen's career has been distilled on to The Essential Leonard Cohen double disc, which features 31 of his best known songs.

An expanded version which adds seven songs on a third disc (The Essential Leonard Cohen 3.0) unfortunately doesn't extend into his last album Dear Heather of 2004 (aside from The Letters), but it fills in gaps with songs from the 70s, including Death of a Ladies' Man.

But as an overview of a career which defies easy analysis, these are useful primers. And of course he sounds like no one other than himself. And no one sounds "Cohenesque".

*Leonard Cohen plays the Vector Arena on October 28 and 29. Tickets are still available for the first night.