Davey Graham, Union Chapel, London

The Sixties casualty who decides on a comeback needs to think carefully. Brian Wilson got round his infirmity by recognising his limitations and peopling the stage with some superb musicians. All he really had to do was prop himself up and entrust matters to his voice, which was largely intact.

Singing is one thing, but it's another to play the guitar to the sublime levels of which Davey Graham was once capable – and to hold an audience all on your own. Revered by such as Jimmy Page, Bert Jansch, Martin Carthy and Paul Simon, Graham, now 66, held out the prospect of something magical when he emerged from decades of obscurity to go on the road again. Sadly, on this occasion, it wasn't to be.

A finger-picker of awesome dexterity, Graham was always much more than an English folkie, embracing Spanish, African and Middle Eastern forms long before anyone thought of world music. He was in many ways his instrument's Glenn Gould, lost in the depths and the intensity of the sounds he was creating, and, like Gould, it seems, a soul in torment.

Whatever image people had of Graham, it surely wasn't that of the rangy figure who bounded on to the stage in navy suit, white shirt and brightly coloured tie. With the manic gleam in his eye, he seemed like a character out of Samuel Beckett.

Graham ran through a set that lasted just an hour and which might kindly be described as under-rehearsed. It was certainly fascinating to watch his way of playing the guitar – high up on the neck – and there were moments when shafts of his former genius shone through, notably on "Sitar Rum", a beautiful Indian raga.

More often there was the sense that the pieces just weren't falling into place, and it was reinforced when Graham repeatedly brought numbers to an abrupt halt as if he had just woken up from a bad dream. It didn't help that it was hard to understand Graham's whiskery chatter between songs, and there was the disappointment of his failure to perform his most famous composition, "Anji". Perhaps under the circumstances the omission was no bad thing.

Could the Union Chapel be haunted? Because I think I just saw the ghost of Davey Graham there.