Evan Parker, The Vortex, London <!-- none onestar twostar fourstar fivestar -->

If there is one art form that comes closest to the music lampooned by The Fast Show's "Jazz Club", it is free jazz. With no discernible metre or pre-determined harmonic progressions, free jazz either operates at the rarified heights of pure improvisation or constitutes a cacophony, depending on your point of view.

The late Benny Green took the latter line. Reviewing Ornette Coleman, one of free jazz's progenitors, at Ronnie Scott's in 1966, he wrote: "The act of criticism is necessarily connected with what the artist is supposed to be doing, and as I haven't the remotest idea what Ornette Coleman is supposed to be doing, all criticism is stilled. It remains only to report what happens when he arrives on the bandstand."

I have some sympathy with Green, and his words came to mind watching Evan Parker and his trio during one of their regular appearances at the Vortex; this is difficult music.

That Parker is a formidable musician is no more a matter of doubt. I have watched him rise, this bearded bear of a man, from the ranks of the Kenny Wheeler big band to blow quite outstanding solos on the tenor saxophone. He combines a gruffness at the lower end, with an expressiveness in the middle similar to that of Michael Brecker. Parker can hold a note (he is renowned for his circular breathing) and shift his sound round as though his tenor was nuzzling about a great tree trunk.

He is equally adept at producing fast, fierce sounds, at times rattling around the depths of his horn; at others, notes appear with an explosiveness the production of which would require a double laxative and prune combo in most other men.

When the backing trio subsides - that is, when the drummer decides to put the pots and pans he has been throwing back on the shelf, and the pianist and bassist stop playing a demented version of The Flight of the Bumblebee - then there is real beauty in this strange but powerful music.

There is something in it. But I find myself no better placed to describe it than Green was. I won't opt for his cheap but funny shot at Coleman and compare Parker's music to a stopped clock - "right at least twice a day". I suspect it's right many more times than that. The hands of this particular clock, though, are barely legible to those of us whose minds cannot reach the height at which Parker wanders.