Pop: Live; Lesson one: the love song

THE UNMASKING of Nick Cave has been a long and gradual process. He first landed on these shores almost two decades ago as the bloodied and deranged front man with The Birthday Party. Transformed thereafter into a solo artist drawn to biblical lust and vengeance, a cabaret act from the dark side and even a novelist of considerable repute, he has consistently subverted expectations about where a cult rock star should go and what he should do next.

The process continued with this performance. Centring on an extended version of a lecture entitled "The Secret Life Of The Love Song", which he first delivered in Vienna last year, Cave now commands a presence that allows him to address an audience from a lectern, a screen behind him highlighting pertinent lyrics.

He cuts an impressively rakish figure, a long bony index finger striking the air for emphasis and grave booming voice extolling an art form he says has all but died in contemporary rock music.

Mapping out the spiritual concerns and deep longing central to his craft, Cave quotes from WH Auden, Lorca and pop sensations Boney M and Kylie Minogue. The latter magically appears in person to recite the words of her pop hit "Better The Devil You Know". A song, he notes with some relish, where Kylie became "love's sacrificial lamb with a groovy techno beat".

It took not only a degree of erudition and eloquence but a measure of theatricality, skilfully employed to overcome understandable nerves at various points, to pull off the lecture conceit. With an inevitable acknowledgement for his late teacher father and a curt dismissal for a lone heckler, Cave managed admirably.

But, of course, his analyses of the love song - funny, effusive and penetrating as it often was - could only go so far in making his case. It was with a judicious selection of his own songs performed during the lecture and in a mini set immediately after it had concluded, that Cave really claimed his territory.

Taking his place at the piano, pounding out harsh Jerry Lee Lewis style chords, he first plunged into the tangled mire of "West Country Girl" while the song's rumoured inspiration, PJ Harvey, looked on approvingly from the stalls. Thereafter the less-is- more ethic practised on his most recent album, The Boatman's Call, took hold with the lucid, feral accompaniment of The Dirty Three.

On "Sad Waters", Warren Ellis's unhinged lonesome violin went deep into the song's glade of mournful memory. Stripped of its demonic drive, the classic death-row contemplation "Mercy Seat" unearthed new depths and character nuance. There was also a beautifully simple, unburnished and, as yet, unrecorded song "Love Letter", which immediately found a place among the songs in which Cave takes a special pride, what he refers to as "my crooked brood of sad-eyed children". Long may he tend to their needs.