JAZZ The Diffy Cult University of Bath

With his black clothing, shaven head and Mephistophelean goatee, the trumpeter Ted Emmett is both the Diffy Cult's leader and its visible eminence noir. Inclined to extravagant gestures, inaudible announcements and sudden fits of pique, he stands in relation to his musicians in the same way an anarchist captain must do to his troops: he knows he should command them but nevertheless remains ideologically opposed to the idea.

At one point, after announcing an arrangement of the standard "Star Eyes", he exited the stage and left the band to its own devices. When the musicians paused, looking quite understandably perplexed, he momentarily returned to say, angrily: "Just play it! Count it in and everything!"

He's a genuinely maverick figure, whose long experience on the fringes of British jazz has been leavened by occasional roles backing pop musicians such as The Teardrop Explodes, which, given the respective temperaments of the saturnine Emmett and the bonkers Julian Cope, could not, one imagines, have been a particularly restful gig.

But Emmett's music can be quite sublime. His compositions and arrangements for this ambitious nonet on this Arts Council-backed tour recall, through the underpinning tuba of Oren Marshall and the three saxes and two trumpets of the front-line, the Gil Evans sound of Miles Davis's Birth of the Cool, as well as the early Sixties experiments of Charles Mingus, Eric Dolphy and Booker Little. Not that Emmett is a retro-copyist. His rich orchestral voicings fit into a British jazz tradition somewhere between the free- music lineage of the Seventies and the English eccentrism of Django Bates, the recent recipient of the Danish Jazzpar Prize, for whose bands Emmett has written.

They also sound wholly contemporary. Dense, brooding themes are lightened by the lyrical piano of the great Pete Jacobsen - England's own Keith Jarrett - and superbly pliant solos by alto saxophonist Steve Buckley, another Bates acolyte.

Driving the whole machine is the astonishingly expressive bass-playing of Paul Rogers, whose free-jazz grounding lends his role as a time-keeper a wonderfully spiky edge, expertly interwoven by Iain Pattinson's subtle drumming. On tenor saxes, Simon Picard's ruminations are balanced by the hell-for-leather bop heroics of Patrick Clahar. Emmett's expressionistic trumpet-lines often take the lead, though the beauty of the band lies principally in the incredibly disciplined ensemble-passages and the hard- won grandeur of the themes.

In a manner that is almost unprecedented in contemporary jazz of any school or nationality, one leaves the concert whistling the tunes as Emmett, clearly a softie at heart, leads the blind pianist from the stage with touching solicitude.