Lee 'Scratch' Perry, Jazz Cafe, London

To Bob Marley he was a genius. To lovers of sonic invention and pioneering dub he is the Phil Spector of reggae, the Original Upsetter, a wilful eccentric and living legend whose back catalogue is constantly repackaged in lovingly compiled box-sets that no self-respecting music lover dare live without.

Yes, indeed – no question, no argument, no critical judgement needed – there is only one Lee "Scratch" Perry; but therein lies the Scratch 22 at the heart of the enigma. As a writer, producer and arranger, Perry – now in his mid-sixties – has few peers. As a performer, however, he seems happy to serve his time as little more than a bizarre sideshow on the strange and forgiving cabaret circuit of summer festivals and student union puff-fests. And tonight, London's Jazz Café is rammed to the rafters with those ready, willing and able to give thanks to the man behind those gleaming little CD packages that get played each time the herb's in the house and the vibes are irie.

Perry's entrance is impressive: he descends the stairs carrying a lighted candle with seven sticks of incense burning from the top; he is resplendent in home-made warrior-king garb, with mirrorballs, glittering found objects and precious things dripping from every available inch of his clothing and microphone. We are rapt, we are awed, we are not worthy etc. But then Perry starts to scat in that rasping roar, scraping sonic sandpaper over the fine aural landscape built up by his musical partner Mad Professor, and the legend is diminished.

And how best to point this out? Aside from the three musicians (bass, drums and keyboards), Mr Perry and the security team, there are maybe a half-dozen black people in the house tonight. But, whatever, Toby and Simon and Davinia and Lucretia are here, Lee "Scratch" Perry is on the stage and all's right with the world. Except, of course, it isn't. And on the day that the Allies advanced towards Baghdad, Perry opened with "Joyful Night Tonight", which contains the timely advice that "I love you/ You love me/ We should live in harmony". Are you listening, world leaders? But Perry will make political points later. He will declare the CIA "vile bloody murderers" and "children killers" and we will hold our lighters aloft (one side-product of Gulf 2; every event, from dub gig to comedy show, is invigorated by these heartfelt displays of political activism). At times, it's true, the pumping dub vibe will carry all with it in its joyful union of deep bass and bouncing feet. At these points, Perry is merely a distraction, ranting "rubadubaduba" or urging the crowd to "shake your head/ shake your head/ I am alive not dead" like the drunk uncle at the family do.

Towards the end of the night, Perry takes off his crown and reveals scarlet-dyed hair. And it's then that I realise who he reminds me of. Imagine, if you dare, a Rastafarian Barbara Cartland. Certainly, Perry's output is as prolific, his love of the limelight as fierce and his individualism as proud. But Dame Barbara never got to curate the South Bank's increasingly intriguing Meltdown festival, as Perry will be doing this June. Those shows should really be worth seeing. Just pray that he doesn't insist on singing at them all.